Module:Date: Difference between revisions
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(support date difference codes 'dhms' and 'hms') |
(Enhanced) |
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-- Date functions for use by other modules. |
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-- I18N and time zones are not supported. |
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local MINUS = '−' -- Unicode U+2212 MINUS SIGN |
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local floor = math.floor |
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local Date, DateDiff, diffmt -- forward declarations |
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local uniq = { 'unique identifier' } |
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local function is_date(t) |
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-- The system used to make a date read-only means there is no unique |
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-- metatable that is conveniently accessible to check. |
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return type(t) == 'table' and t._id == uniq |
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end |
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local function is_diff(t) |
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return type(t) == 'table' and getmetatable(t) == diffmt |
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end |
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local function _list_join(list, sep) |
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return table.concat(list, sep) |
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end |
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local function collection() |
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-- Return a table to hold items. |
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return { |
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n = 0, |
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add = function (self, item) |
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self.n = self.n + 1 |
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self[self.n] = item |
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end, |
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join = _list_join, |
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} |
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end |
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local function strip_to_nil(text) |
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-- If text is a string, return its trimmed content, or nil if empty. |
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-- Otherwise return text (convenient when Date fields are provided from |
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-- another module which may pass a string, a number, or another type). |
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if type(text) == 'string' then |
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text = text:match('(%S.-)%s*$') |
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end |
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return text |
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end |
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local function is_leap_year(year, calname) |
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-- Return true if year is a leap year. |
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if calname == 'Julian' then |
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return year % 4 == 0 |
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end |
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return (year % 4 == 0 and year % 100 ~= 0) or year % 400 == 0 |
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end |
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local function days_in_month(year, month, calname) |
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-- Return number of days (1..31) in given month (1..12). |
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if month == 2 and is_leap_year(year, calname) then |
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return 29 |
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end |
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return ({ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 })[month] |
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end |
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local function h_m_s(time) |
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-- Return hour, minute, second extracted from fraction of a day. |
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time = floor(time * 24 * 3600 + 0.5) -- number of seconds |
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local second = time % 60 |
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time = floor(time / 60) |
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return floor(time / 60), time % 60, second |
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end |
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local function hms(date) |
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-- Return fraction of a day from date's time, where (0 <= fraction < 1) |
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-- if the values are valid, but could be anything if outside range. |
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return (date.hour + (date.minute + date.second / 60) / 60) / 24 |
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end |
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local function julian_date(date) |
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-- Return jd, jdz from a Julian or Gregorian calendar date where |
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-- jd = Julian date and its fractional part is zero at noon |
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-- jdz = same, but assume time is 00:00:00 if no time given |
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-- http://www.tondering.dk/claus/cal/julperiod.php#formula |
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-- Testing shows this works for all dates from year -9999 to 9999! |
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-- JDN 0 is the 24-hour period starting at noon UTC on Monday |
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-- 1 January 4713 BC = (-4712, 1, 1) Julian calendar |
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-- 24 November 4714 BC = (-4713, 11, 24) Gregorian calendar |
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local offset |
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local a = floor((14 - date.month)/12) |
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local y = date.year + 4800 - a |
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if date.calendar == 'Julian' then |
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offset = floor(y/4) - 32083 |
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else |
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offset = floor(y/4) - floor(y/100) + floor(y/400) - 32045 |
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end |
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local m = date.month + 12*a - 3 |
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local jd = date.day + floor((153*m + 2)/5) + 365*y + offset |
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if date.hastime then |
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jd = jd + hms(date) - 0.5 |
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return jd, jd |
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end |
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return jd, jd - 0.5 |
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end |
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local function set_date_from_jd(date) |
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-- Set the fields of table date from its Julian date field. |
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-- Return true if date is valid. |
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-- http://www.tondering.dk/claus/cal/julperiod.php#formula |
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-- This handles the proleptic Julian and Gregorian calendars. |
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-- Negative Julian dates are not defined but they work. |
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local calname = date.calendar |
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local low, high -- min/max limits for date ranges −9999-01-01 to 9999-12-31 |
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if calname == 'Gregorian' then |
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low, high = -1930999.5, 5373484.49999 |
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elseif calname == 'Julian' then |
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low, high = -1931076.5, 5373557.49999 |
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else |
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return |
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end |
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local jd = date.jd |
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if not (type(jd) == 'number' and low <= jd and jd <= high) then |
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return |
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end |
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local jdn = floor(jd) |
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if date.hastime then |
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local time = jd - jdn -- 0 <= time < 1 |
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if time >= 0.5 then -- if at or after midnight of next day |
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jdn = jdn + 1 |
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time = time - 0.5 |
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else |
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time = time + 0.5 |
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end |
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date.hour, date.minute, date.second = h_m_s(time) |
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else |
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date.second = 0 |
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date.minute = 0 |
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date.hour = 0 |
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end |
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local b, c |
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if calname == 'Julian' then |
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b = 0 |
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c = jdn + 32082 |
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else -- Gregorian |
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local a = jdn + 32044 |
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b = floor((4*a + 3)/146097) |
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c = a - floor(146097*b/4) |
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end |
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local d = floor((4*c + 3)/1461) |
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local e = c - floor(1461*d/4) |
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local m = floor((5*e + 2)/153) |
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date.day = e - floor((153*m + 2)/5) + 1 |
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date.month = m + 3 - 12*floor(m/10) |
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date.year = 100*b + d - 4800 + floor(m/10) |
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return true |
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end |
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local function fix_numbers(numbers, y, m, d, H, M, S, partial, hastime, calendar) |
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-- Put the result of normalizing the given values in table numbers. |
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-- The result will have valid m, d values if y is valid; caller checks y. |
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-- The logic of PHP mktime is followed where m or d can be zero to mean |
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-- the previous unit, and -1 is the one before that, etc. |
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-- Positive values carry forward. |
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local date |
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if not (1 <= m and m <= 12) then |
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date = Date(y, 1, 1) |
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if not date then return end |
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date = date + ((m - 1) .. 'm') |
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y, m = date.year, date.month |
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end |
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local days_hms |
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if not partial then |
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if hastime and H and M and S then |
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if not (0 <= H and H <= 23 and |
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0 <= M and M <= 59 and |
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0 <= S and S <= 59) then |
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days_hms = hms({ hour = H, minute = M, second = S }) |
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end |
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end |
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if days_hms or not (1 <= d and d <= days_in_month(y, m, calendar)) then |
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date = date or Date(y, m, 1) |
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if not date then return end |
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date = date + (d - 1 + (days_hms or 0)) |
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y, m, d = date.year, date.month, date.day |
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if days_hms then |
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H, M, S = date.hour, date.minute, date.second |
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end |
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end |
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end |
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numbers.year = y |
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numbers.month = m |
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numbers.day = d |
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if days_hms then |
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-- Don't set H unless it was valid because a valid H will set hastime. |
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numbers.hour = H |
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numbers.minute = M |
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numbers.second = S |
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end |
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end |
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local function set_date_from_numbers(date, numbers, options) |
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-- Set the fields of table date from numeric values. |
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-- Return true if date is valid. |
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if type(numbers) ~= 'table' then |
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return |
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end |
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local y = numbers.year or date.year |
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local m = numbers.month or date.month |
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local d = numbers.day or date.day |
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local H = numbers.hour |
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local M = numbers.minute or date.minute or 0 |
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local S = numbers.second or date.second or 0 |
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local need_fix |
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if y and m and d then |
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date.partial = nil |
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if not (-9999 <= y and y <= 9999 and |
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1 <= m and m <= 12 and |
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1 <= d and d <= days_in_month(y, m, date.calendar)) then |
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if not date.want_fix then |
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return |
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end |
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need_fix = true |
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end |
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elseif y and date.partial then |
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if d or not (-9999 <= y and y <= 9999) then |
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return |
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end |
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if m and not (1 <= m and m <= 12) then |
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if not date.want_fix then |
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return |
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end |
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need_fix = true |
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end |
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else |
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return |
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end |
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if date.partial then |
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H = nil -- ignore any time |
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M = nil |
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S = nil |
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else |
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if H then |
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-- It is not possible to set M or S without also setting H. |
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date.hastime = true |
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else |
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H = 0 |
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end |
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if not (0 <= H and H <= 23 and |
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0 <= M and M <= 59 and |
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0 <= S and S <= 59) then |
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if date.want_fix then |
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need_fix = true |
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else |
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return |
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end |
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end |
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end |
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date.want_fix = nil |
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if need_fix then |
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fix_numbers(numbers, y, m, d, H, M, S, date.partial, date.hastime, date.calendar) |
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return set_date_from_numbers(date, numbers, options) |
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end |
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date.year = y -- -9999 to 9999 ('n BC' → year = 1 - n) |
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date.month = m -- 1 to 12 (may be nil if partial) |
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date.day = d -- 1 to 31 (* = nil if partial) |
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date.hour = H -- 0 to 59 (*) |
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date.minute = M -- 0 to 59 (*) |
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date.second = S -- 0 to 59 (*) |
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if type(options) == 'table' then |
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for _, k in ipairs({ 'am', 'era', 'format' }) do |
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if options[k] then |
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date.options[k] = options[k] |
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end |
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end |
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end |
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return true |
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end |
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local function make_option_table(options1, options2) |
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-- If options1 is a string, return a table with its settings, or |
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-- if it is a table, use its settings. |
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-- Missing options are set from table options2 or defaults. |
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-- If a default is used, a flag is set so caller knows the value was not intentionally set. |
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-- Valid option settings are: |
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-- am: 'am', 'a.m.', 'AM', 'A.M.' |
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-- 'pm', 'p.m.', 'PM', 'P.M.' (each has same meaning as corresponding item above) |
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-- era: 'BCMINUS', 'BCNEGATIVE', 'BC', 'B.C.', 'BCE', 'B.C.E.', 'AD', 'A.D.', 'CE', 'C.E.' |
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-- Option am = 'am' does not mean the hour is AM; it means 'am' or 'pm' is used, depending on the hour, |
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-- and am = 'pm' has the same meaning. |
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-- Similarly, era = 'BC' means 'BC' is used if year <= 0. |
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-- BCMINUS displays a MINUS if year < 0 and the display format does not include %{era}. |
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-- BCNEGATIVE is similar but displays a hyphen. |
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local result = { bydefault = {} } |
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if type(options1) == 'table' then |
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result.am = options1.am |
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result.era = options1.era |
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elseif type(options1) == 'string' then |
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-- Example: 'am:AM era:BC' or 'am=AM era=BC'. |
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for item in options1:gmatch('%S+') do |
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local lhs, rhs = item:match('^(%w+)[:=](.+)$') |
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if lhs then |
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result[lhs] = rhs |
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end |
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end |
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end |
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options2 = type(options2) == 'table' and options2 or {} |
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local defaults = { am = 'am', era = 'BC' } |
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for k, v in pairs(defaults) do |
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if not result[k] then |
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if options2[k] then |
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result[k] = options2[k] |
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else |
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result[k] = v |
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result.bydefault[k] = true |
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end |
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end |
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end |
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return result |
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end |
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local ampm_options = { |
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-- lhs = input text accepted as an am/pm option |
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-- rhs = code used internally |
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['am'] = 'am', |
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['AM'] = 'AM', |
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['a.m.'] = 'a.m.', |
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['A.M.'] = 'A.M.', |
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['pm'] = 'am', -- same as am |
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['PM'] = 'AM', |
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['p.m.'] = 'a.m.', |
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['P.M.'] = 'A.M.', |
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} |
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local era_text = { |
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-- Text for displaying an era with a positive year (after adjusting |
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-- by replacing year with 1 - year if date.year <= 0). |
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-- options.era = { year<=0 , year>0 } |
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['BCMINUS'] = { 'BC' , '' , isbc = true, sign = MINUS }, |
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['BCNEGATIVE'] = { 'BC' , '' , isbc = true, sign = '-' }, |
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['BC'] = { 'BC' , '' , isbc = true }, |
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['B.C.'] = { 'B.C.' , '' , isbc = true }, |
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['BCE'] = { 'BCE' , '' , isbc = true }, |
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['B.C.E.'] = { 'B.C.E.', '' , isbc = true }, |
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['AD'] = { 'BC' , 'AD' }, |
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['A.D.'] = { 'B.C.' , 'A.D.' }, |
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['CE'] = { 'BCE' , 'CE' }, |
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['C.E.'] = { 'B.C.E.', 'C.E.' }, |
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} |
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local function get_era_for_year(era, year) |
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return (era_text[era] or era_text['BC'])[year > 0 and 2 or 1] or '' |
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end |
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local function strftime(date, format, options) |
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-- Return date formatted as a string using codes similar to those |
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-- in the C strftime library function. |
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local sformat = string.format |
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local shortcuts = { |
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['%c'] = '%-I:%M %p %-d %B %-Y %{era}', -- date and time: 2:30 pm 1 April 2016 |
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['%x'] = '%-d %B %-Y %{era}', -- date: 1 April 2016 |
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['%X'] = '%-I:%M %p', -- time: 2:30 pm |
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} |
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if shortcuts[format] then |
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format = shortcuts[format] |
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end |
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local codes = { |
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a = { field = 'dayabbr' }, |
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A = { field = 'dayname' }, |
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b = { field = 'monthabbr' }, |
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B = { field = 'monthname' }, |
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u = { fmt = '%d' , field = 'dowiso' }, |
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w = { fmt = '%d' , field = 'dow' }, |
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d = { fmt = '%02d', fmt2 = '%d', field = 'day' }, |
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m = { fmt = '%02d', fmt2 = '%d', field = 'month' }, |
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Y = { fmt = '%04d', fmt2 = '%d', field = 'year' }, |
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H = { fmt = '%02d', fmt2 = '%d', field = 'hour' }, |
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M = { fmt = '%02d', fmt2 = '%d', field = 'minute' }, |
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S = { fmt = '%02d', fmt2 = '%d', field = 'second' }, |
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j = { fmt = '%03d', fmt2 = '%d', field = 'dayofyear' }, |
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I = { fmt = '%02d', fmt2 = '%d', field = 'hour', special = 'hour12' }, |
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p = { field = 'hour', special = 'am' }, |
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} |
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options = make_option_table(options, date.options) |
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local amopt = options.am |
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local eraopt = options.era |
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local function replace_code(spaces, modifier, id) |
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local code = codes[id] |
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if code then |
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local fmt = code.fmt |
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if modifier == '-' and code.fmt2 then |
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fmt = code.fmt2 |
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end |
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local value = date[code.field] |
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if not value then |
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return nil -- an undefined field in a partial date |
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end |
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local special = code.special |
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if special then |
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if special == 'hour12' then |
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value = value % 12 |
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value = value == 0 and 12 or value |
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elseif special == 'am' then |
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local ap = ({ |
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['a.m.'] = { 'a.m.', 'p.m.' }, |
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['AM'] = { 'AM', 'PM' }, |
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['A.M.'] = { 'A.M.', 'P.M.' }, |
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})[ampm_options[amopt]] or { 'am', 'pm' } |
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return (spaces == '' and '' or ' ') .. (value < 12 and ap[1] or ap[2]) |
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end |
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end |
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if code.field == 'year' then |
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local sign = (era_text[eraopt] or {}).sign |
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if not sign or format:find('%{era}', 1, true) then |
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sign = '' |
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if value <= 0 then |
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value = 1 - value |
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end |
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else |
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if value >= 0 then |
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sign = '' |
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else |
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value = -value |
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end |
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end |
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return spaces .. sign .. sformat(fmt, value) |
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end |
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return spaces .. (fmt and sformat(fmt, value) or value) |
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end |
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end |
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local function replace_property(spaces, id) |
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if id == 'era' then |
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-- Special case so can use local era option. |
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local result = get_era_for_year(eraopt, date.year) |
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if result == '' then |
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return '' |
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end |
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return (spaces == '' and '' or ' ') .. result |
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end |
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local result = date[id] |
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if type(result) == 'string' then |
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return spaces .. result |
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end |
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if type(result) == 'number' then |
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return spaces .. tostring(result) |
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end |
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if type(result) == 'boolean' then |
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return spaces .. (result and '1' or '0') |
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end |
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-- This occurs if id is an undefined field in a partial date, or is the name of a function. |
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return nil |
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end |
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local PERCENT = '\127PERCENT\127' |
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return (format |
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:gsub('%%%%', PERCENT) |
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:gsub('(%s*)%%{(%w+)}', replace_property) |
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:gsub('(%s*)%%(%-?)(%a)', replace_code) |
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:gsub(PERCENT, '%%') |
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) |
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end |
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local function _date_text(date, fmt, options) |
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-- Return a formatted string representing the given date. |
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if not is_date(date) then |
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error('date:text: need a date (use "date:text()" with a colon)', 2) |
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end |
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if type(fmt) == 'string' and fmt:match('%S') then |
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if fmt:find('%', 1, true) then |
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return strftime(date, fmt, options) |
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end |
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elseif date.partial then |
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fmt = date.month and 'my' or 'y' |
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else |
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fmt = 'dmy' |
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if date.hastime then |
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fmt = (date.second > 0 and 'hms ' or 'hm ') .. fmt |
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end |
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end |
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local function bad_format() |
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-- For consistency with other format processing, return given format |
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-- (or cleaned format if original was not a string) if invalid. |
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return mw.text.nowiki(fmt) |
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end |
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if date.partial then |
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-- Ignore days in standard formats like 'ymd'. |
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if fmt == 'ym' or fmt == 'ymd' then |
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fmt = date.month and '%Y-%m %{era}' or '%Y %{era}' |
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elseif fmt == 'my' or fmt == 'dmy' or fmt == 'mdy' then |
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fmt = date.month and '%B %-Y %{era}' or '%-Y %{era}' |
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elseif fmt == 'y' then |
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fmt = date.month and '%-Y %{era}' or '%-Y %{era}' |
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else |
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return bad_format() |
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end |
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return strftime(date, fmt, options) |
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end |
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local function hm_fmt() |
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local plain = make_option_table(options, date.options).bydefault.am |
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return plain and '%H:%M' or '%-I:%M %p' |
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end |
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local need_time = date.hastime |
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local t = collection() |
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for item in fmt:gmatch('%S+') do |
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local f |
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if item == 'hm' then |
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f = hm_fmt() |
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need_time = false |
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elseif item == 'hms' then |
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f = '%H:%M:%S' |
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need_time = false |
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elseif item == 'ymd' then |
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f = '%Y-%m-%d %{era}' |
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elseif item == 'mdy' then |
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f = '%B %-d, %-Y %{era}' |
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elseif item == 'dmy' then |
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f = '%-d %B %-Y %{era}' |
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else |
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return bad_format() |
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end |
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t:add(f) |
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end |
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fmt = t:join(' ') |
|||
if need_time then |
|||
fmt = hm_fmt() .. ' ' .. fmt |
|||
end |
|||
return strftime(date, fmt, options) |
|||
end |
|||
local day_info = { |
|||
-- 0=Sun to 6=Sat |
|||
[0] = { 'Sun', 'Sunday' }, |
|||
{ 'Mon', 'Monday' }, |
|||
{ 'Tue', 'Tuesday' }, |
|||
{ 'Wed', 'Wednesday' }, |
|||
{ 'Thu', 'Thursday' }, |
|||
{ 'Fri', 'Friday' }, |
|||
{ 'Sat', 'Saturday' }, |
|||
} |
|||
local month_info = { |
|||
-- 1=Jan to 12=Dec |
|||
{ 'Jan', 'January' }, |
|||
{ 'Feb', 'February' }, |
|||
{ 'Mar', 'March' }, |
|||
{ 'Apr', 'April' }, |
|||
{ 'May', 'May' }, |
|||
{ 'Jun', 'June' }, |
|||
{ 'Jul', 'July' }, |
|||
{ 'Aug', 'August' }, |
|||
{ 'Sep', 'September' }, |
|||
{ 'Oct', 'October' }, |
|||
{ 'Nov', 'November' }, |
|||
{ 'Dec', 'December' }, |
|||
} |
|||
local function name_to_number(text, translate) |
|||
if type(text) == 'string' then |
|||
return translate[text:lower()] |
|||
end |
|||
end |
|||
local function day_number(text) |
|||
return name_to_number(text, { |
|||
sun = 0, sunday = 0, |
|||
mon = 1, monday = 1, |
|||
tue = 2, tuesday = 2, |
|||
wed = 3, wednesday = 3, |
|||
thu = 4, thursday = 4, |
|||
fri = 5, friday = 5, |
|||
sat = 6, saturday = 6, |
|||
}) |
|||
end |
|||
local function month_number(text) |
|||
return name_to_number(text, { |
|||
jan = 1, january = 1, |
|||
feb = 2, february = 2, |
|||
mar = 3, march = 3, |
|||
apr = 4, april = 4, |
|||
may = 5, |
|||
jun = 6, june = 6, |
|||
jul = 7, july = 7, |
|||
aug = 8, august = 8, |
|||
sep = 9, september = 9, sept = 9, |
|||
oct = 10, october = 10, |
|||
nov = 11, november = 11, |
|||
dec = 12, december = 12, |
|||
}) |
|||
end |
|||
local function _list_text(list, fmt) |
|||
-- Return a list of formatted strings from a list of dates. |
|||
if not type(list) == 'table' then |
|||
error('date:list:text: need "list:text()" with a colon', 2) |
|||
end |
|||
local result = { join = _list_join } |
|||
for i, date in ipairs(list) do |
|||
result[i] = date:text(fmt) |
|||
end |
|||
return result |
|||
end |
|||
local function _date_list(date, spec) |
|||
-- Return a possibly empty numbered table of dates meeting the specification. |
|||
-- Dates in the list are in ascending order (oldest date first). |
|||
-- The spec should be a string of form "<count> <day> <op>" |
|||
-- where each item is optional and |
|||
-- count = number of items wanted in list |
|||
-- day = abbreviation or name such as Mon or Monday |
|||
-- op = >, >=, <, <= (default is > meaning after date) |
|||
-- If no count is given, the list is for the specified days in date's month. |
|||
-- The default day is date's day. |
|||
-- The spec can also be a positive or negative number: |
|||
-- -5 is equivalent to '5 <' |
|||
-- 5 is equivalent to '5' which is '5 >' |
|||
if not is_date(date) then |
|||
error('date:list: need a date (use "date:list()" with a colon)', 2) |
|||
end |
|||
local list = { text = _list_text } |
|||
if date.partial then |
|||
return list |
|||
end |
|||
local count, offset, operation |
|||
local ops = { |
|||
['>='] = { before = false, include = true }, |
|||
['>'] = { before = false, include = false }, |
|||
['<='] = { before = true , include = true }, |
|||
['<'] = { before = true , include = false }, |
|||
} |
|||
if spec then |
|||
if type(spec) == 'number' then |
|||
count = floor(spec + 0.5) |
|||
if count < 0 then |
|||
count = -count |
|||
operation = ops['<'] |
|||
end |
|||
elseif type(spec) == 'string' then |
|||
local num, day, op = spec:match('^%s*(%d*)%s*(%a*)%s*([<>=]*)%s*$') |
|||
if not num then |
|||
return list |
|||
end |
|||
if num ~= '' then |
|||
count = tonumber(num) |
|||
end |
|||
if day ~= '' then |
|||
local dow = day_number(day:gsub('[sS]$', '')) -- accept plural days |
|||
if not dow then |
|||
return list |
|||
end |
|||
offset = dow - date.dow |
|||
end |
|||
operation = ops[op] |
|||
else |
|||
return list |
|||
end |
|||
end |
|||
offset = offset or 0 |
|||
operation = operation or ops['>'] |
|||
local datefrom, dayfirst, daylast |
|||
if operation.before then |
|||
if offset > 0 or (offset == 0 and not operation.include) then |
|||
offset = offset - 7 |
|||
end |
|||
if count then |
|||
if count > 1 then |
|||
offset = offset - 7*(count - 1) |
|||
end |
|||
datefrom = date + offset |
|||
else |
|||
daylast = date.day + offset |
|||
dayfirst = daylast % 7 |
|||
if dayfirst == 0 then |
|||
dayfirst = 7 |
|||
end |
|||
end |
|||
else |
|||
if offset < 0 or (offset == 0 and not operation.include) then |
|||
offset = offset + 7 |
|||
end |
|||
if count then |
|||
datefrom = date + offset |
|||
else |
|||
dayfirst = date.day + offset |
|||
daylast = date.monthdays |
|||
end |
|||
end |
|||
if not count then |
|||
if daylast < dayfirst then |
|||
return list |
|||
end |
|||
count = floor((daylast - dayfirst)/7) + 1 |
|||
datefrom = Date(date, {day = dayfirst}) |
|||
end |
|||
for i = 1, count do |
|||
if not datefrom then break end -- exceeds date limits |
|||
list[i] = datefrom |
|||
datefrom = datefrom + 7 |
|||
end |
|||
return list |
|||
end |
|||
-- A table to get the current date/time (UTC), but only if needed. |
|||
local current = setmetatable({}, { |
|||
__index = function (self, key) |
|||
local d = os.date('!*t') |
|||
self.year = d.year |
|||
self.month = d.month |
|||
self.day = d.day |
|||
self.hour = d.hour |
|||
self.minute = d.min |
|||
self.second = d.sec |
|||
return rawget(self, key) |
|||
end }) |
|||
local function extract_date(newdate, text) |
|||
-- Parse the date/time in text and return n, o where |
|||
-- n = table of numbers with date/time fields |
|||
-- o = table of options for AM/PM or AD/BC or format, if any |
|||
-- or return nothing if date is known to be invalid. |
|||
-- Caller determines if the values in n are valid. |
|||
-- A year must be positive ('1' to '9999'); use 'BC' for BC. |
|||
-- In a y-m-d string, the year must be four digits to avoid ambiguity |
|||
-- ('0001' to '9999'). The only way to enter year <= 0 is by specifying |
|||
-- the date as three numeric parameters like ymd Date(-1, 1, 1). |
|||
-- Dates of form d/m/y, m/d/y, y/m/d are rejected as potentially ambiguous. |
|||
local date, options = {}, {} |
|||
if text:sub(-1) == 'Z' then |
|||
-- Extract date/time from a Wikidata timestamp. |
|||
-- The year can be 1 to 16 digits but this module handles 1 to 4 digits only. |
|||
-- Examples: '+2016-06-21T14:30:00Z', '-0000000180-00-00T00:00:00Z'. |
|||
local sign, y, m, d, H, M, S = text:match('^([+%-])(%d+)%-(%d%d)%-(%d%d)T(%d%d):(%d%d):(%d%d)Z$') |
|||
if sign then |
|||
y = tonumber(y) |
|||
if sign == '-' and y > 0 then |
|||
y = -y |
|||
end |
|||
if y <= 0 then |
|||
options.era = 'BCE' |
|||
end |
|||
date.year = y |
|||
m = tonumber(m) |
|||
d = tonumber(d) |
|||
H = tonumber(H) |
|||
M = tonumber(M) |
|||
S = tonumber(S) |
|||
if m == 0 then |
|||
newdate.partial = true |
|||
return date, options |
|||
end |
|||
date.month = m |
|||
if d == 0 then |
|||
newdate.partial = true |
|||
return date, options |
|||
end |
|||
date.day = d |
|||
if H > 0 or M > 0 or S > 0 then |
|||
date.hour = H |
|||
date.minute = M |
|||
date.second = S |
|||
end |
|||
return date, options |
|||
end |
|||
return |
|||
end |
|||
local function extract_ymd(item) |
|||
-- Called when no day or month has been set. |
|||
local y, m, d = item:match('^(%d%d%d%d)%-(%w+)%-(%d%d?)$') |
|||
if y then |
|||
if date.year then |
|||
return |
|||
end |
|||
if m:match('^%d%d?$') then |
|||
m = tonumber(m) |
|||
else |
|||
m = month_number(m) |
|||
end |
|||
if m then |
|||
date.year = tonumber(y) |
|||
date.month = m |
|||
date.day = tonumber(d) |
|||
return true |
|||
end |
|||
end |
|||
end |
|||
local function extract_day_or_year(item) |
|||
-- Called when a day would be valid, or |
|||
-- when a year would be valid if no year has been set and partial is set. |
|||
local number, suffix = item:match('^(%d%d?%d?%d?)(.*)$') |
|||
if number then |
|||
local n = tonumber(number) |
|||
if #number <= 2 and n <= 31 then |
|||
suffix = suffix:lower() |
|||
if suffix == '' or suffix == 'st' or suffix == 'nd' or suffix == 'rd' or suffix == 'th' then |
|||
date.day = n |
|||
return true |
|||
end |
|||
elseif suffix == '' and newdate.partial and not date.year then |
|||
date.year = n |
|||
return true |
|||
end |
|||
end |
|||
end |
|||
local function extract_month(item) |
|||
-- A month must be given as a name or abbreviation; a number could be ambiguous. |
|||
local m = month_number(item) |
|||
if m then |
|||
date.month = m |
|||
return true |
|||
end |
|||
end |
|||
local function extract_time(item) |
|||
local h, m, s = item:match('^(%d%d?):(%d%d)(:?%d*)$') |
|||
if date.hour or not h then |
|||
return |
|||
end |
|||
if s ~= '' then |
|||
s = s:match('^:(%d%d)$') |
|||
if not s then |
|||
return |
|||
end |
|||
end |
|||
date.hour = tonumber(h) |
|||
date.minute = tonumber(m) |
|||
date.second = tonumber(s) -- nil if empty string |
|||
return true |
|||
end |
|||
local item_count = 0 |
|||
local index_time |
|||
local function set_ampm(item) |
|||
local H = date.hour |
|||
if H and not options.am and index_time + 1 == item_count then |
|||
options.am = ampm_options[item] -- caller checked this is not nil |
|||
if item:match('^[Aa]') then |
|||
if not (1 <= H and H <= 12) then |
|||
return |
|||
end |
|||
if H == 12 then |
|||
date.hour = 0 |
|||
end |
|||
else |
|||
if not (1 <= H and H <= 23) then |
|||
return |
|||
end |
|||
if H <= 11 then |
|||
date.hour = H + 12 |
|||
end |
|||
end |
|||
return true |
|||
end |
|||
end |
|||
for item in text:gsub(',', ' '):gsub(' ', ' '):gmatch('%S+') do |
|||
item_count = item_count + 1 |
|||
if era_text[item] then |
|||
-- Era is accepted in peculiar places. |
|||
if options.era then |
|||
return |
|||
end |
|||
options.era = item |
|||
elseif ampm_options[item] then |
|||
if not set_ampm(item) then |
|||
return |
|||
end |
|||
elseif item:find(':', 1, true) then |
|||
if not extract_time(item) then |
|||
return |
|||
end |
|||
index_time = item_count |
|||
elseif date.day and date.month then |
|||
if date.year then |
|||
return -- should be nothing more so item is invalid |
|||
end |
|||
if not item:match('^(%d%d?%d?%d?)$') then |
|||
return |
|||
end |
|||
date.year = tonumber(item) |
|||
elseif date.day then |
|||
if not extract_month(item) then |
|||
return |
|||
end |
|||
elseif date.month then |
|||
if not extract_day_or_year(item) then |
|||
return |
|||
end |
|||
elseif extract_month(item) then |
|||
options.format = 'mdy' |
|||
elseif extract_ymd(item) then |
|||
options.format = 'ymd' |
|||
elseif extract_day_or_year(item) then |
|||
if date.day then |
|||
options.format = 'dmy' |
|||
end |
|||
else |
|||
return |
|||
end |
|||
end |
|||
if not date.year or date.year == 0 then |
|||
return |
|||
end |
|||
local era = era_text[options.era] |
|||
if era and era.isbc then |
|||
date.year = 1 - date.year |
|||
end |
|||
return date, options |
|||
end |
|||
local function date_add_sub(lhs, rhs, is_sub) |
|||
-- Return a new date from calculating (lhs + rhs) or (lhs - rhs), |
|||
-- or return nothing if invalid. |
|||
-- The result is nil if the calculated date exceeds allowable limits. |
|||
-- Caller ensures that lhs is a date; its properties are copied for the new date. |
|||
if lhs.partial then |
|||
-- Adding to a partial is not supported. |
|||
-- Can subtract a date or partial from a partial, but this is not called for that. |
|||
return |
|||
end |
|||
local function is_prefix(text, word, minlen) |
|||
local n = #text |
|||
return (minlen or 1) <= n and n <= #word and text == word:sub(1, n) |
|||
end |
|||
local function do_days(n) |
|||
local forcetime, jd |
|||
if floor(n) == n then |
|||
jd = lhs.jd |
|||
else |
|||
forcetime = not lhs.hastime |
|||
jd = lhs.jdz |
|||
end |
|||
jd = jd + (is_sub and -n or n) |
|||
if forcetime then |
|||
jd = tostring(jd) |
|||
if not jd:find('.', 1, true) then |
|||
jd = jd .. '.0' |
|||
end |
|||
end |
|||
return Date(lhs, 'juliandate', jd) |
|||
end |
|||
if type(rhs) == 'number' then |
|||
-- Add/subtract days, including fractional days. |
|||
return do_days(rhs) |
|||
end |
|||
if type(rhs) == 'string' then |
|||
-- rhs is a single component like '26m' or '26 months' (with optional sign). |
|||
-- Fractions like '3.25d' are accepted for the units which are handled as days. |
|||
local sign, numstr, id = rhs:match('^%s*([+-]?)([%d%.]+)%s*(%a+)$') |
|||
if sign then |
|||
if sign == '-' then |
|||
is_sub = not (is_sub and true or false) |
|||
end |
|||
local y, m, days |
|||
local num = tonumber(numstr) |
|||
if not num then |
|||
return |
|||
end |
|||
id = id:lower() |
|||
if is_prefix(id, 'years') then |
|||
y = num |
|||
m = 0 |
|||
elseif is_prefix(id, 'months') then |
|||
y = floor(num / 12) |
|||
m = num % 12 |
|||
elseif is_prefix(id, 'weeks') then |
|||
days = num * 7 |
|||
elseif is_prefix(id, 'days') then |
|||
days = num |
|||
elseif is_prefix(id, 'hours') then |
|||
days = num / 24 |
|||
elseif is_prefix(id, 'minutes', 3) then |
|||
days = num / (24 * 60) |
|||
elseif is_prefix(id, 'seconds') then |
|||
days = num / (24 * 3600) |
|||
else |
|||
return |
|||
end |
|||
if days then |
|||
return do_days(days) |
|||
end |
|||
if numstr:find('.', 1, true) then |
|||
return |
|||
end |
|||
if is_sub then |
|||
y = -y |
|||
m = -m |
|||
end |
|||
assert(-11 <= m and m <= 11) |
|||
y = lhs.year + y |
|||
m = lhs.month + m |
|||
if m > 12 then |
|||
y = y + 1 |
|||
m = m - 12 |
|||
elseif m < 1 then |
|||
y = y - 1 |
|||
m = m + 12 |
|||
end |
|||
local d = math.min(lhs.day, days_in_month(y, m, lhs.calendar)) |
|||
return Date(lhs, y, m, d) |
|||
end |
|||
end |
|||
if is_diff(rhs) then |
|||
local days = rhs.age_days |
|||
if (is_sub or false) ~= (rhs.isnegative or false) then |
|||
days = -days |
|||
end |
|||
return lhs + days |
|||
end |
|||
end |
|||
local full_date_only = { |
|||
dayabbr = true, |
|||
dayname = true, |
|||
dow = true, |
|||
dayofweek = true, |
|||
dowiso = true, |
|||
dayofweekiso = true, |
|||
dayofyear = true, |
|||
gsd = true, |
|||
juliandate = true, |
|||
jd = true, |
|||
jdz = true, |
|||
jdnoon = true, |
|||
} |
|||
-- Metatable for a date's calculated fields. |
|||
local datemt = { |
|||
__index = function (self, key) |
|||
if rawget(self, 'partial') then |
|||
if full_date_only[key] then return end |
|||
if key == 'monthabbr' or key == 'monthdays' or key == 'monthname' then |
|||
if not self.month then return end |
|||
end |
|||
end |
|||
local value |
|||
if key == 'dayabbr' then |
|||
value = day_info[self.dow][1] |
|||
elseif key == 'dayname' then |
|||
value = day_info[self.dow][2] |
|||
elseif key == 'dow' then |
|||
value = (self.jdnoon + 1) % 7 -- day-of-week 0=Sun to 6=Sat |
|||
elseif key == 'dayofweek' then |
|||
value = self.dow |
|||
elseif key == 'dowiso' then |
|||
value = (self.jdnoon % 7) + 1 -- ISO day-of-week 1=Mon to 7=Sun |
|||
elseif key == 'dayofweekiso' then |
|||
value = self.dowiso |
|||
elseif key == 'dayofyear' then |
|||
local first = Date(self.year, 1, 1, self.calendar).jdnoon |
|||
value = self.jdnoon - first + 1 -- day-of-year 1 to 366 |
|||
elseif key == 'era' then |
|||
-- Era text (never a negative sign) from year and options. |
|||
value = get_era_for_year(self.options.era, self.year) |
|||
elseif key == 'format' then |
|||
value = self.options.format or 'dmy' |
|||
elseif key == 'gsd' then |
|||
-- GSD = 1 from 00:00:00 to 23:59:59 on 1 January 1 AD Gregorian calendar, |
|||
-- which is from jd 1721425.5 to 1721426.49999. |
|||
value = floor(self.jd - 1721424.5) |
|||
elseif key == 'juliandate' or key == 'jd' or key == 'jdz' then |
|||
local jd, jdz = julian_date(self) |
|||
rawset(self, 'juliandate', jd) |
|||
rawset(self, 'jd', jd) |
|||
rawset(self, 'jdz', jdz) |
|||
return key == 'jdz' and jdz or jd |
|||
elseif key == 'jdnoon' then |
|||
-- Julian date at noon (an integer) on the calendar day when jd occurs. |
|||
value = floor(self.jd + 0.5) |
|||
elseif key == 'isleapyear' then |
|||
value = is_leap_year(self.year, self.calendar) |
|||
elseif key == 'monthabbr' then |
|||
value = month_info[self.month][1] |
|||
elseif key == 'monthdays' then |
|||
value = days_in_month(self.year, self.month, self.calendar) |
|||
elseif key == 'monthname' then |
|||
value = month_info[self.month][2] |
|||
end |
|||
if value ~= nil then |
|||
rawset(self, key, value) |
|||
return value |
|||
end |
|||
end, |
|||
} |
|||
-- Date operators. |
|||
local function mt_date_add(lhs, rhs) |
|||
if not is_date(lhs) then |
|||
lhs, rhs = rhs, lhs -- put date on left (it must be a date for this to have been called) |
|||
end |
|||
return date_add_sub(lhs, rhs) |
|||
end |
|||
local function mt_date_sub(lhs, rhs) |
|||
if is_date(lhs) then |
|||
if is_date(rhs) then |
|||
return DateDiff(lhs, rhs) |
|||
end |
|||
return date_add_sub(lhs, rhs, true) |
|||
end |
|||
end |
|||
local function mt_date_concat(lhs, rhs) |
|||
return tostring(lhs) .. tostring(rhs) |
|||
end |
|||
local function mt_date_tostring(self) |
|||
return self:text() |
|||
end |
|||
local function mt_date_eq(lhs, rhs) |
|||
-- Return true if dates identify same date/time where, for example, |
|||
-- Date(-4712, 1, 1, 'Julian') == Date(-4713, 11, 24, 'Gregorian') is true. |
|||
-- This is called only if lhs and rhs have the same type and the same metamethod. |
|||
if lhs.partial or rhs.partial then |
|||
-- One date is partial; the other is a partial or a full date. |
|||
-- The months may both be nil, but must be the same. |
|||
return lhs.year == rhs.year and lhs.month == rhs.month and lhs.calendar == rhs.calendar |
|||
end |
|||
return lhs.jdz == rhs.jdz |
|||
end |
|||
local function mt_date_lt(lhs, rhs) |
|||
-- Return true if lhs < rhs, for example, |
|||
-- Date('1 Jan 2016') < Date('06:00 1 Jan 2016') is true. |
|||
-- This is called only if lhs and rhs have the same type and the same metamethod. |
|||
if lhs.partial or rhs.partial then |
|||
-- One date is partial; the other is a partial or a full date. |
|||
if lhs.calendar ~= rhs.calendar then |
|||
return lhs.calendar == 'Julian' |
|||
end |
|||
if lhs.partial then |
|||
lhs = lhs.partial.first |
|||
end |
|||
if rhs.partial then |
|||
rhs = rhs.partial.first |
|||
end |
|||
end |
|||
return lhs.jdz < rhs.jdz |
|||
end |
|||
--[[ Examples of syntax to construct a date: |
|||
Date(y, m, d, 'julian') default calendar is 'gregorian' |
|||
Date(y, m, d, H, M, S, 'julian') |
|||
Date('juliandate', jd, 'julian') if jd contains "." text output includes H:M:S |
|||
Date('currentdate') |
|||
Date('currentdatetime') |
|||
Date('1 April 1995', 'julian') parse date from text |
|||
Date('1 April 1995 AD', 'julian') using an era sets a flag to do the same for output |
|||
Date('04:30:59 1 April 1995', 'julian') |
|||
Date(date) copy of an existing date |
|||
Date(date, t) same, updated with y,m,d,H,M,S fields from table t |
|||
Date(t) date with y,m,d,H,M,S fields from table t |
|||
]] |
|||
function Date(...) -- for forward declaration above |
|||
-- Return a table holding a date assuming a uniform calendar always applies |
|||
-- (proleptic Gregorian calendar or proleptic Julian calendar), or |
|||
-- return nothing if date is invalid. |
|||
-- A partial date has a valid year, however its month may be nil, and |
|||
-- its day and time fields are nil. |
|||
-- Field partial is set to false (if a full date) or a table (if a partial date). |
|||
local calendars = { julian = 'Julian', gregorian = 'Gregorian' } |
|||
local newdate = { |
|||
_id = uniq, |
|||
calendar = 'Gregorian', -- default is Gregorian calendar |
|||
hastime = false, -- true if input sets a time |
|||
hour = 0, -- always set hour/minute/second so don't have to handle nil |
|||
minute = 0, |
|||
second = 0, |
|||
options = {}, |
|||
list = _date_list, |
|||
text = _date_text, |
|||
} |
|||
local argtype, datetext, is_copy, jd_number, tnums |
|||
local numindex = 0 |
|||
local numfields = { 'year', 'month', 'day', 'hour', 'minute', 'second' } |
|||
local numbers = {} |
|||
for _, v in ipairs({...}) do |
|||
v = strip_to_nil(v) |
|||
local vlower = type(v) == 'string' and v:lower() or nil |
|||
if v == nil then |
|||
-- Ignore empty arguments after stripping so modules can directly pass template parameters. |
|||
elseif calendars[vlower] then |
|||
newdate.calendar = calendars[vlower] |
|||
elseif vlower == 'partial' then |
|||
newdate.partial = true |
|||
elseif vlower == 'fix' then |
|||
newdate.want_fix = true |
|||
elseif is_date(v) then |
|||
-- Copy existing date (items can be overridden by other arguments). |
|||
if is_copy or tnums then |
|||
return |
|||
end |
|||
is_copy = true |
|||
newdate.calendar = v.calendar |
|||
newdate.partial = v.partial |
|||
newdate.hastime = v.hastime |
|||
newdate.options = v.options |
|||
newdate.year = v.year |
|||
newdate.month = v.month |
|||
newdate.day = v.day |
|||
newdate.hour = v.hour |
|||
newdate.minute = v.minute |
|||
newdate.second = v.second |
|||
elseif type(v) == 'table' then |
|||
if tnums then |
|||
return |
|||
end |
|||
tnums = {} |
|||
local tfields = { year=1, month=1, day=1, hour=2, minute=2, second=2 } |
|||
for tk, tv in pairs(v) do |
|||
if tfields[tk] then |
|||
tnums[tk] = tonumber(tv) |
|||
end |
|||
if tfields[tk] == 2 then |
|||
newdate.hastime = true |
|||
end |
|||
end |
|||
else |
|||
local num = tonumber(v) |
|||
if not num and argtype == 'setdate' and numindex == 1 then |
|||
num = month_number(v) |
|||
end |
|||
if num then |
|||
if not argtype then |
|||
argtype = 'setdate' |
|||
end |
|||
if argtype == 'setdate' and numindex < 6 then |
|||
numindex = numindex + 1 |
|||
numbers[numfields[numindex]] = num |
|||
elseif argtype == 'juliandate' and not jd_number then |
|||
jd_number = num |
|||
if type(v) == 'string' then |
|||
if v:find('.', 1, true) then |
|||
newdate.hastime = true |
|||
end |
|||
elseif num ~= floor(num) then |
|||
-- The given value was a number. The time will be used |
|||
-- if the fractional part is nonzero. |
|||
newdate.hastime = true |
|||
end |
|||
else |
|||
return |
|||
end |
|||
elseif argtype then |
|||
return |
|||
elseif type(v) == 'string' then |
|||
if v == 'currentdate' or v == 'currentdatetime' or v == 'juliandate' then |
|||
argtype = v |
|||
else |
|||
argtype = 'datetext' |
|||
datetext = v |
|||
end |
|||
else |
|||
return |
|||
end |
|||
end |
|||
end |
|||
if argtype == 'datetext' then |
|||
if tnums or not set_date_from_numbers(newdate, extract_date(newdate, datetext)) then |
|||
return |
|||
end |
|||
elseif argtype == 'juliandate' then |
|||
newdate.partial = nil |
|||
newdate.jd = jd_number |
|||
if not set_date_from_jd(newdate) then |
|||
return |
|||
end |
|||
elseif argtype == 'currentdate' or argtype == 'currentdatetime' then |
|||
newdate.partial = nil |
|||
newdate.year = current.year |
|||
newdate.month = current.month |
|||
newdate.day = current.day |
|||
if argtype == 'currentdatetime' then |
|||
newdate.hour = current.hour |
|||
newdate.minute = current.minute |
|||
newdate.second = current.second |
|||
newdate.hastime = true |
|||
end |
|||
newdate.calendar = 'Gregorian' -- ignore any given calendar name |
|||
elseif argtype == 'setdate' then |
|||
if tnums or not set_date_from_numbers(newdate, numbers) then |
|||
return |
|||
end |
|||
elseif not (is_copy or tnums) then |
|||
return |
|||
end |
|||
if tnums then |
|||
newdate.jd = nil -- force recalculation in case jd was set before changes from tnums |
|||
if not set_date_from_numbers(newdate, tnums) then |
|||
return |
|||
end |
|||
end |
|||
if newdate.partial then |
|||
local year = newdate.year |
|||
local month = newdate.month |
|||
local first = Date(year, month or 1, 1, newdate.calendar) |
|||
month = month or 12 |
|||
local last = Date(year, month, days_in_month(year, month), newdate.calendar) |
|||
newdate.partial = { first = first, last = last } |
|||
else |
|||
newdate.partial = false -- avoid index lookup |
|||
end |
|||
setmetatable(newdate, datemt) |
|||
local readonly = {} |
|||
local mt = { |
|||
__index = newdate, |
|||
__newindex = function(t, k, v) error('date.' .. tostring(k) .. ' is read-only', 2) end, |
|||
__add = mt_date_add, |
|||
__sub = mt_date_sub, |
|||
__concat = mt_date_concat, |
|||
__tostring = mt_date_tostring, |
|||
__eq = mt_date_eq, |
|||
__lt = mt_date_lt, |
|||
} |
|||
return setmetatable(readonly, mt) |
|||
end |
|||
local function _diff_age(diff, code, options) |
|||
-- Return a tuple of integer values from diff as specified by code, except that |
|||
-- each integer may be a list of two integers for a diff with a partial date, or |
|||
-- return nil if the code is not supported. |
|||
-- If want round, the least significant unit is rounded to nearest whole unit. |
|||
-- For a duration, an extra day is added. |
|||
local wantround, wantduration, wantrange |
|||
if type(options) == 'table' then |
|||
wantround = options.round |
|||
wantduration = options.duration |
|||
wantrange = options.range |
|||
else |
|||
wantround = options |
|||
end |
|||
if not is_diff(diff) then |
|||
local f = wantduration and 'duration' or 'age' |
|||
error(f .. ': need a date difference (use "diff:' .. f .. '()" with a colon)', 2) |
|||
end |
|||
if diff.partial then |
|||
-- Ignore wantround, wantduration. |
|||
local function choose(v) |
|||
if type(v) == 'table' then |
|||
if not wantrange then |
|||
-- Example: Date('partial', 2005) - Date('partial', 2001) gives |
|||
-- diff.years = { 3, 4 } to show the range of possible results. |
|||
-- If do not want a range, choose the second value as more expected. |
|||
return v[2] |
|||
end |
|||
end |
|||
return v |
|||
end |
|||
if code == 'ym' or code == 'ymd' then |
|||
if not wantrange and diff.iszero then |
|||
-- This avoids an unexpected result such as |
|||
-- Date('partial', 2001) - Date('partial', 2001) |
|||
-- giving diff = { years = 0, months = { 0, 11 } } |
|||
-- which would be reported as 0 years and 11 months. |
|||
return 0, 0 |
|||
end |
|||
return choose(diff.partial.years), choose(diff.partial.months) |
|||
end |
|||
if code == 'y' then |
|||
return choose(diff.partial.years) |
|||
end |
|||
return nil |
|||
end |
|||
local extra_days = wantduration and 1 or 0 |
|||
if code == 'wd' or code == 'w' or code == 'd' then |
|||
local offset = wantround and 0.5 or 0 |
|||
local days = diff.age_days + extra_days |
|||
if code == 'wd' or code == 'd' then |
|||
days = floor(days + offset) |
|||
if code == 'd' then |
|||
return days |
|||
end |
|||
return floor(days/7), days % 7 |
|||
end |
|||
return floor(days/7 + offset) |
|||
end |
|||
local H, M, S = diff.hours, diff.minutes, diff.seconds |
|||
if code == 'dh' or code == 'dhm' or code == 'dhms' or code == 'h' or code == 'hm' or code == 'hms' then |
|||
local days = floor(diff.age_days + extra_days) |
|||
local inc_hour |
|||
if wantround then |
|||
if code == 'dh' or code == 'h' then |
|||
if M >= 30 then |
|||
inc_hour = true |
|||
end |
|||
elseif code == 'dhm' or code == 'hm' then |
|||
if S >= 30 then |
|||
M = M + 1 |
|||
if M >= 60 then |
|||
M = 0 |
|||
inc_hour = true |
|||
end |
|||
end |
|||
else |
|||
-- Nothing needed because S is an integer. |
|||
end |
|||
if inc_hour then |
|||
H = H + 1 |
|||
if H >= 24 then |
|||
H = 0 |
|||
days = days + 1 |
|||
end |
|||
end |
|||
end |
|||
if code == 'dh' or code == 'dhm' or code == 'dhms' then |
|||
if code == 'dh' then |
|||
return days, H |
|||
elseif code == 'dhm' then |
|||
return days, H, M |
|||
else |
|||
return days, H, M, S |
|||
end |
|||
end |
|||
local hours = days * 24 + H |
|||
if code == 'h' then |
|||
return hours |
|||
elseif code == 'hm' then |
|||
return hours, M |
|||
end |
|||
return hours, M, S |
|||
end |
|||
if wantround then |
|||
local inc_hour |
|||
if code == 'ymdh' or code == 'ymwdh' then |
|||
if M >= 30 then |
|||
inc_hour = true |
|||
end |
|||
elseif code == 'ymdhm' or code == 'ymwdhm' then |
|||
if S >= 30 then |
|||
M = M + 1 |
|||
if M >= 60 then |
|||
M = 0 |
|||
inc_hour = true |
|||
end |
|||
end |
|||
elseif code == 'ymd' or code == 'ymwd' or code == 'yd' or code == 'md' then |
|||
if H >= 12 then |
|||
extra_days = extra_days + 1 |
|||
end |
|||
end |
|||
if inc_hour then |
|||
H = H + 1 |
|||
if H >= 24 then |
|||
H = 0 |
|||
extra_days = extra_days + 1 |
|||
end |
|||
end |
|||
end |
|||
local y, m, d = diff.years, diff.months, diff.days |
|||
if extra_days > 0 then |
|||
d = d + extra_days |
|||
if d > 28 or code == 'yd' then |
|||
-- Recalculate in case have passed a month. |
|||
diff = diff.date1 + extra_days - diff.date2 |
|||
y, m, d = diff.years, diff.months, diff.days |
|||
end |
|||
end |
|||
if code == 'ymd' then |
|||
return y, m, d |
|||
elseif code == 'yd' then |
|||
if y > 0 then |
|||
-- It is known that diff.date1 > diff.date2. |
|||
diff = diff.date1 - (diff.date2 + (y .. 'y')) |
|||
end |
|||
return y, floor(diff.age_days) |
|||
elseif code == 'md' then |
|||
return y * 12 + m, d |
|||
elseif code == 'ym' or code == 'm' then |
|||
if wantround then |
|||
if d >= 16 then |
|||
m = m + 1 |
|||
if m >= 12 then |
|||
m = 0 |
|||
y = y + 1 |
|||
end |
|||
end |
|||
end |
|||
if code == 'ym' then |
|||
return y, m |
|||
end |
|||
return y * 12 + m |
|||
elseif code == 'ymw' then |
|||
local weeks = floor(d/7) |
|||
if wantround then |
|||
local days = d % 7 |
|||
if days > 3 or (days == 3 and H >= 12) then |
|||
weeks = weeks + 1 |
|||
end |
|||
end |
|||
return y, m, weeks |
|||
elseif code == 'ymwd' then |
|||
return y, m, floor(d/7), d % 7 |
|||
elseif code == 'ymdh' then |
|||
return y, m, d, H |
|||
elseif code == 'ymwdh' then |
|||
return y, m, floor(d/7), d % 7, H |
|||
elseif code == 'ymdhm' then |
|||
return y, m, d, H, M |
|||
elseif code == 'ymwdhm' then |
|||
return y, m, floor(d/7), d % 7, H, M |
|||
end |
|||
if code == 'y' then |
|||
if wantround and m >= 6 then |
|||
y = y + 1 |
|||
end |
|||
return y |
|||
end |
|||
return nil |
|||
end |
|||
local function _diff_duration(diff, code, options) |
|||
if type(options) ~= 'table' then |
|||
options = { round = options } |
|||
end |
|||
options.duration = true |
|||
return _diff_age(diff, code, options) |
|||
end |
|||
-- Metatable for some operations on date differences. |
|||
diffmt = { -- for forward declaration above |
|||
__concat = function (lhs, rhs) |
|||
return tostring(lhs) .. tostring(rhs) |
|||
end, |
|||
__tostring = function (self) |
|||
return tostring(self.age_days) |
|||
end, |
|||
__index = function (self, key) |
|||
local value |
|||
if key == 'age_days' then |
|||
if rawget(self, 'partial') then |
|||
local function jdz(date) |
|||
return (date.partial and date.partial.first or date).jdz |
|||
end |
|||
value = jdz(self.date1) - jdz(self.date2) |
|||
else |
|||
value = self.date1.jdz - self.date2.jdz |
|||
end |
|||
end |
|||
if value ~= nil then |
|||
rawset(self, key, value) |
|||
return value |
|||
end |
|||
end, |
|||
} |
|||
function DateDiff(date1, date2) -- for forward declaration above |
|||
-- Return a table with the difference between two dates (date1 - date2). |
|||
-- The difference is negative if date1 is older than date2. |
|||
-- Return nothing if invalid. |
|||
-- If d = date1 - date2 then |
|||
-- date1 = date2 + d |
|||
-- If date1 >= date2 and the dates have no H:M:S time specified then |
|||
-- date1 = date2 + (d.years..'y') + (d.months..'m') + d.days |
|||
-- where the larger time units are added first. |
|||
-- The result of Date(2015,1,x) + '1m' is Date(2015,2,28) for |
|||
-- x = 28, 29, 30, 31. That means, for example, |
|||
-- d = Date(2015,3,3) - Date(2015,1,31) |
|||
-- gives d.years, d.months, d.days = 0, 1, 3 (excluding date1). |
|||
if not (is_date(date1) and is_date(date2) and date1.calendar == date2.calendar) then |
|||
return |
|||
end |
|||
local isnegative = false |
|||
local iszero = false |
|||
if date1 < date2 then |
|||
isnegative = true |
|||
date1, date2 = date2, date1 |
|||
elseif date1 == date2 then |
|||
iszero = true |
|||
end |
|||
-- It is known that date1 >= date2 (period is from date2 to date1). |
|||
if date1.partial or date2.partial then |
|||
-- Two partial dates might have timelines: |
|||
---------------------A=================B--- date1 is from A to B inclusive |
|||
--------C=======D-------------------------- date2 is from C to D inclusive |
|||
-- date1 > date2 iff A > C (date1.partial.first > date2.partial.first) |
|||
-- The periods can overlap ('April 2001' - '2001'): |
|||
-------------A===B------------------------- A=2001-04-01 B=2001-04-30 |
|||
--------C=====================D------------ C=2001-01-01 D=2001-12-31 |
|||
local function zdiff(date1, date2) |
|||
local diff = date1 - date2 |
|||
if diff.isnegative then |
|||
return { years = 0, months = 0 } |
|||
end |
|||
return diff |
|||
end |
|||
local function getdate(date, which) |
|||
return date.partial and date.partial[which] or date |
|||
end |
|||
local maxdiff = zdiff(getdate(date1, 'last'), getdate(date2, 'first')) |
|||
local mindiff = zdiff(getdate(date1, 'first'), getdate(date2, 'last')) |
|||
local years, months |
|||
if maxdiff.years == mindiff.years then |
|||
years = maxdiff.years |
|||
if maxdiff.months == mindiff.months then |
|||
months = maxdiff.months |
|||
else |
|||
months = { mindiff.months, maxdiff.months } |
|||
end |
|||
else |
|||
years = { mindiff.years, maxdiff.years } |
|||
end |
|||
return setmetatable({ |
|||
date1 = date1, |
|||
date2 = date2, |
|||
partial = { years = years, months = months }, |
|||
isnegative = isnegative, |
|||
iszero = iszero, |
|||
age = _diff_age, |
|||
duration = _diff_duration, |
|||
}, diffmt) |
|||
end |
|||
local y1, m1 = date1.year, date1.month |
|||
local y2, m2 = date2.year, date2.month |
|||
local years = y1 - y2 |
|||
local months = m1 - m2 |
|||
local d1 = date1.day + hms(date1) |
|||
local d2 = date2.day + hms(date2) |
|||
local days, time |
|||
if d1 >= d2 then |
|||
days = d1 - d2 |
|||
else |
|||
months = months - 1 |
|||
-- Get days in previous month (before the "to" date) given December has 31 days. |
|||
local dpm = m1 > 1 and days_in_month(y1, m1 - 1, date1.calendar) or 31 |
|||
if d2 >= dpm then |
|||
days = d1 - hms(date2) |
|||
else |
|||
days = dpm - d2 + d1 |
|||
end |
|||
end |
|||
if months < 0 then |
|||
years = years - 1 |
|||
months = months + 12 |
|||
end |
|||
days, time = math.modf(days) |
|||
local H, M, S = h_m_s(time) |
|||
return setmetatable({ |
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date1 = date1, |
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date2 = date2, |
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partial = false, -- avoid index lookup |
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years = years, |
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months = months, |
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days = days, |
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hours = H, |
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minutes = M, |
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seconds = S, |
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isnegative = isnegative, |
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iszero = iszero, |
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age = _diff_age, |
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duration = _diff_duration, |
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}, diffmt) |
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end |
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return { |
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_current = current, |
|||
_Date = Date, |
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_days_in_month = days_in_month, |
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} |
Revision as of 15:23, 10 October 2017
Documentation for this module may be created at Module:Date/doc