Module:Date: Difference between revisions

    (fix bug where Date('2016-06-01') - Date('2016-05-31 23:00') gave 1 day instead of 1 hour)
    (update from Module:Date/sandbox; major refactor to support new features in Module:Age)
    Line 69: Line 69:


    local function hms(date)
    local function hms(date)
    -- Return fraction of a day (0 <= fraction < 1) from date's time.
    -- Return fraction of a day from date's time, where (0 <= fraction < 1)
    -- if the values are valid, but could be anything if outside range.
    return (date.hour + (date.minute + date.second / 60) / 60) / 24
    return (date.hour + (date.minute + date.second / 60) / 60) / 24
    end
    end
    Line 149: Line 150:
    date.year = 100*b + d - 4800 + floor(m/10)
    date.year = 100*b + d - 4800 + floor(m/10)
    return true
    return true
    end
    local function fix_numbers(numbers, y, m, d, H, M, S, partial, hastime, calendar)
    -- Put the result of normalizing the given values in table numbers.
    -- The result will have valid m, d values if y is valid; caller checks y.
    -- The logic of PHP mktime is followed where m or d can be zero to mean
    -- the previous unit, and -1 is the one before that, etc.
    -- Positive values carry forward.
    local date
    if not (1 <= m and m <= 12) then
    date = Date(y, 1, 1)
    if not date then return end
    date = date + ((m - 1) .. 'm')
    y, m = date.year, date.month
    end
    local days_hms
    if not partial then
    if hastime and H and M and S then
    if not (0 <= H and H <= 23 and
    0 <= M and M <= 59 and
    0 <= S and S <= 59) then
    days_hms = hms({ hour = H, minute = M, second = S })
    end
    end
    if days_hms or not (1 <= d and d <= days_in_month(y, m, calendar)) then
    date = date or Date(y, m, 1)
    if not date then return end
    date = date + (d - 1 + (days_hms or 0))
    y, m, d = date.year, date.month, date.day
    if days_hms then
    H, M, S = date.hour, date.minute, date.second
    end
    end
    end
    numbers.year = y
    numbers.month = m
    numbers.day = d
    if days_hms then
    -- Don't set H unless it was valid because a valid H will set hastime.
    numbers.hour = H
    numbers.minute = M
    numbers.second = S
    end
    end
    end


    Line 163: Line 207:
    local M = numbers.minute or date.minute or 0
    local M = numbers.minute or date.minute or 0
    local S = numbers.second or date.second or 0
    local S = numbers.second or date.second or 0
    if not (y and m and d) or not
    local need_fix
    (-9999 <= y and y <= 9999 and
    if y and m and d then
    date.partial = nil
    if not (-9999 <= y and y <= 9999 and
    1 <= m and m <= 12 and
    1 <= m and m <= 12 and
    1 <= d and d <= days_in_month(y, m, date.calendar)) then
    1 <= d and d <= days_in_month(y, m, date.calendar)) then
    if not date.want_fix then
    return
    end
    need_fix = true
    end
    elseif y and date.partial then
    if d or not (-9999 <= y and y <= 9999) then
    return
    end
    if m and not (1 <= m and m <= 12) then
    if not date.want_fix then
    return
    end
    need_fix = true
    end
    else
    return
    return
    end
    end
    if H then
    if date.partial then
    -- It is not possible to set M or S without also setting H.
    H = nil  -- ignore any time
    date.hastime = true
    M = nil
    S = nil
    else
    else
    H = date.hour or 0
    if H then
    -- It is not possible to set M or S without also setting H.
    date.hastime = true
    else
    H = 0
    end
    if not (0 <= H and H <= 23 and
    0 <= M and M <= 59 and
    0 <= S and S <= 59) then
    if date.want_fix then
    need_fix = true
    else
    return
    end
    end
    end
    end
    if not (0 <= H and H <= 23 and
    date.want_fix = nil
    0 <= M and M <= 59 and
    if need_fix then
    0 <= S and S <= 59) then
    fix_numbers(numbers, y, m, d, H, M, S, date.partial, date.hastime, date.calendar)
    return
    return set_date_from_numbers(date, numbers, options)
    end
    end
    date.year = y    -- -9999 to 9999 ('n BC' → year = 1 - n)
    date.year = y    -- -9999 to 9999 ('n BC' → year = 1 - n)
    date.month = m  -- 1 to 12
    date.month = m  -- 1 to 12 (may be nil if partial)
    date.day = d    -- 1 to 31
    date.day = d    -- 1 to 31 (* = nil if partial)
    date.hour = H    -- 0 to 59
    date.hour = H    -- 0 to 59 (*)
    date.minute = M  -- 0 to 59
    date.minute = M  -- 0 to 59 (*)
    date.second = S  -- 0 to 59
    date.second = S  -- 0 to 59 (*)
    if type(options) == 'table' then
    if type(options) == 'table' then
    for _, k in ipairs({ 'am', 'era', 'format' }) do
    for _, k in ipairs({ 'am', 'era', 'format' }) do
    Line 311: Line 388:
    end
    end
    local value = date[code.field]
    local value = date[code.field]
    if not value then
    return nil  -- an undefined field in a partial date
    end
    local special = code.special
    local special = code.special
    if special then
    if special then
    Line 363: Line 443:
    return  spaces .. (result and '1' or '0')
    return  spaces .. (result and '1' or '0')
    end
    end
    -- This occurs, for example, if id is the name of a function.
    -- This occurs if id is an undefined field in a partial date, or is the name of a function.
    return nil
    return nil
    end
    end
    Line 384: Line 464:
    return strftime(date, fmt, options)
    return strftime(date, fmt, options)
    end
    end
    elseif date.partial then
    fmt = date.month and 'my' or 'y'
    else
    else
    fmt = 'dmy'
    fmt = 'dmy'
    Line 389: Line 471:
    fmt = (date.second > 0 and 'hms ' or 'hm ') .. fmt
    fmt = (date.second > 0 and 'hms ' or 'hm ') .. fmt
    end
    end
    end
    local function bad_format()
    -- For consistency with other format processing, return given format
    -- (or cleaned format if original was not a string) if invalid.
    return mw.text.nowiki(fmt)
    end
    if date.partial then
    -- Ignore days in standard formats like 'ymd'.
    if fmt == 'ym' or fmt == 'ymd' then
    fmt = date.month and '%Y-%m %{era}' or '%Y %{era}'
    elseif fmt == 'my' or fmt == 'dmy' or fmt == 'mdy' then
    fmt = date.month and '%B %-Y %{era}' or '%-Y %{era}'
    elseif fmt == 'y' then
    fmt = date.month and '%-Y %{era}' or '%-Y %{era}'
    else
    return bad_format()
    end
    return strftime(date, fmt, options)
    end
    end
    local function hm_fmt()
    local function hm_fmt()
    Line 411: Line 511:
    f = '%-d %B %-Y %{era}'
    f = '%-d %B %-Y %{era}'
    else
    else
    error('date:text: invalid format', 2)
    return bad_format()
    end
    end
    t:add(f)
    t:add(f)
    Line 477: Line 577:
    jul = 7, july = 7,
    jul = 7, july = 7,
    aug = 8, august = 8,
    aug = 8, august = 8,
    sep = 9, september = 9,
    sep = 9, september = 9, sept = 9,
    oct = 10, october = 10,
    oct = 10, october = 10,
    nov = 11, november = 11,
    nov = 11, november = 11,
    Line 509: Line 609:
    --  -5 is equivalent to '5 <'
    --  -5 is equivalent to '5 <'
    --  5  is equivalent to '5' which is '5 >'
    --  5  is equivalent to '5' which is '5 >'
    local list = { text = _list_text }
    if not is_date(date) then
    if not is_date(date) then
    error('date:list: need a date (use "date:list()" with a colon)', 2)
    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
    end
    local count, offset, operation
    local count, offset, operation
    Line 607: Line 710:
    end })
    end })


    local function extract_date(text)
    local function extract_date(newdate, text)
    -- Parse the date/time in text and return n, o where
    -- Parse the date/time in text and return n, o where
    --  n = table of numbers with date/time fields
    --  n = table of numbers with date/time fields
    Line 619: Line 722:
    -- Dates of form d/m/y, m/d/y, y/m/d are rejected as potentially ambiguous.
    -- Dates of form d/m/y, m/d/y, y/m/d are rejected as potentially ambiguous.
    local date, options = {}, {}
    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$')
    if sign then
    y = tonumber(y)
    if sign == '-' and y > 0 then
    y = -y
    end
    if y <= 0 then
    options.era = 'BCE'
    end
    date.year = y
    m = tonumber(m)
    d = tonumber(d)
    H = tonumber(H)
    M = tonumber(M)
    S = tonumber(S)
    if m == 0 then
    newdate.partial = true
    return date, options
    end
    date.month = m
    if d == 0 then
    newdate.partial = true
    return date, options
    end
    date.day = d
    if H > 0 or M > 0 or S > 0 then
    date.hour = H
    date.minute = M
    date.second = S
    end
    return date, options
    end
    return
    end
    local function extract_ymd(item)
    local function extract_ymd(item)
    local ystr, mstr, dstr = item:match('^(%d%d%d%d)%-(%w+)%-(%d%d?)$')
    -- Called when no day or month has been set.
    if ystr then
    local y, m, d = item:match('^(%d%d%d%d)%-(%w+)%-(%d%d?)$')
    local m
    if y then
    if mstr:match('^%d%d?$') then
    if date.year then
    m = tonumber(mstr)
    return
    end
    if m:match('^%d%d?$') then
    m = tonumber(m)
    else
    else
    m = month_number(mstr)
    m = month_number(m)
    end
    end
    if m then
    if m then
    options.format = 'ymd'
    date.year = tonumber(y)
    date.year = tonumber(ystr)
    date.month = m
    date.month = m
    date.day = tonumber(dstr)
    date.day = tonumber(d)
    return true
    end
    end
    end
    local function extract_day_or_year(item)
    -- Called when a day would be valid, or
    -- when a year would be valid if no year has been set and partial is set.
    local number, suffix = item:match('^(%d%d?%d?%d?)(.*)$')
    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
    return true
    end
    end
    Line 666: Line 827:
    local H = date.hour
    local H = date.hour
    if H and not options.am and index_time + 1 == item_count then
    if H and not options.am and index_time + 1 == item_count then
    options.am = ampm_options[item]
    options.am = ampm_options[item] -- caller checked this is not nil
    if item:match('^[Aa]') then
    if item:match('^[Aa]') then
    if not (1 <= H and H <= 12) then
    if not (1 <= H and H <= 12) then
    Line 715: Line 876:
    end
    end
    elseif date.month then
    elseif date.month then
    if not item:match('^(%d%d?)$') then
    if not extract_day_or_year(item) then
    return
    return
    end
    end
    date.day = tonumber(item)
    elseif extract_month(item) then
    elseif not extract_ymd(item) then
    options.format = 'mdy'
    if item:match('^(%d%d?)$') then
    elseif extract_ymd(item) then
    date.day = tonumber(item)
    options.format = 'ymd'
    elseif extract_day_or_year(item) then
    if date.day then
    options.format = 'dmy'
    options.format = 'dmy'
    elseif extract_month(item) then
    options.format = 'mdy'
    else
    return
    end
    end
    else
    return
    end
    end
    end
    end
    Line 745: Line 906:
    -- The result is nil if the calculated date exceeds allowable limits.
    -- 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.
    -- 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 function is_prefix(text, word, minlen)
    local n = #text
    local n = #text
    Line 771: Line 937:
    end
    end
    if type(rhs) == 'string' then
    if type(rhs) == 'string' then
    -- rhs is a single component like '26m' or '26 months' (unsigned integer only).
    -- rhs is a single component like '26m' or '26 months' (with optional sign).
    local num, id = rhs:match('^%s*(%d+)%s*(%a+)$')
    -- Fractions like '3.25d' are accepted for the units which are handled as days.
    if num then
    local sign, numstr, id = rhs:match('^%s*([+-]?)([%d%.]+)%s*(%a+)$')
    local y, m
    if sign then
    num = tonumber(num)
    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()
    id = id:lower()
    if is_prefix(id, 'years') then
    if is_prefix(id, 'years') then
    Line 784: Line 957:
    m = num % 12
    m = num % 12
    elseif is_prefix(id, 'weeks') then
    elseif is_prefix(id, 'weeks') then
    return do_days(num * 7)
    days = num * 7
    elseif is_prefix(id, 'days') then
    elseif is_prefix(id, 'days') then
    return do_days(num)
    days = num
    elseif is_prefix(id, 'hours') then
    elseif is_prefix(id, 'hours') then
    return do_days(num / 24)
    days = num / 24
    elseif is_prefix(id, 'minutes', 3) then
    elseif is_prefix(id, 'minutes', 3) then
    return do_days(num / (24 * 60))
    days = num / (24 * 60)
    elseif is_prefix(id, 'seconds') then
    elseif is_prefix(id, 'seconds') then
    return do_days(num / (24 * 3600))
    days = num / (24 * 3600)
    else
    else
    return
    end
    if days then
    return do_days(days)
    end
    if numstr:find('.', 1, true) then
    return
    return
    end
    end
    Line 822: Line 1,001:
    end
    end
    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.
    -- Metatable for a date's calculated fields.
    local datemt = {
    local datemt = {
    __index = function (self, key)
    __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
    local value
    if key == 'dayabbr' then
    if key == 'dayabbr' then
    Line 905: Line 1,105:
    -- Date(-4712, 1, 1, 'Julian') == Date(-4713, 11, 24, 'Gregorian') is true.
    -- Date(-4712, 1, 1, 'Julian') == Date(-4713, 11, 24, 'Gregorian') is true.
    -- This is only called if lhs and rhs have the same metatable.
    -- This is only called if lhs and rhs have the same metatable.
    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
    return lhs.jdz == rhs.jdz
    end
    end
    Line 912: Line 1,117:
    -- Date('1 Jan 2016') < Date('06:00 1 Jan 2016') is true.
    -- Date('1 Jan 2016') < Date('06:00 1 Jan 2016') is true.
    -- This is only called if lhs and rhs have the same metatable.
    -- This is only called if lhs and rhs have the same metatable.
    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
    return lhs.jdz < rhs.jdz
    end
    end
    Line 932: Line 1,149:
    -- (proleptic Gregorian calendar or proleptic Julian calendar), or
    -- (proleptic Gregorian calendar or proleptic Julian calendar), or
    -- return nothing if date is invalid.
    -- 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 calendars = { julian = 'Julian', gregorian = 'Gregorian' }
    local newdate = {
    local newdate = {
    Line 955: Line 1,175:
    elseif calendars[vlower] then
    elseif calendars[vlower] then
    newdate.calendar = calendars[vlower]
    newdate.calendar = calendars[vlower]
    elseif vlower == 'partial' then
    newdate.partial = true
    elseif vlower == 'fix' then
    newdate.want_fix = true
    elseif is_date(v) then
    elseif is_date(v) then
    -- Copy existing date (items can be overridden by other arguments).
    -- Copy existing date (items can be overridden by other arguments).
    Line 962: Line 1,186:
    is_copy = true
    is_copy = true
    newdate.calendar = v.calendar
    newdate.calendar = v.calendar
    newdate.partial = v.partial
    newdate.hastime = v.hastime
    newdate.hastime = v.hastime
    newdate.options = v.options
    newdate.options = v.options
    Line 1,025: Line 1,250:
    end
    end
    if argtype == 'datetext' then
    if argtype == 'datetext' then
    if tnums or not set_date_from_numbers(newdate, extract_date(datetext)) then
    if tnums or not set_date_from_numbers(newdate, extract_date(newdate, datetext)) then
    return
    return
    end
    end
    elseif argtype == 'juliandate' then
    elseif argtype == 'juliandate' then
    newdate.partial = nil
    newdate.jd = jd_number
    newdate.jd = jd_number
    if not set_date_from_jd(newdate) then
    if not set_date_from_jd(newdate) then
    Line 1,034: Line 1,260:
    end
    end
    elseif argtype == 'currentdate' or argtype == 'currentdatetime' then
    elseif argtype == 'currentdate' or argtype == 'currentdatetime' then
    newdate.partial = nil
    newdate.year = current.year
    newdate.year = current.year
    newdate.month = current.month
    newdate.month = current.month
    Line 1,056: Line 1,283:
    return
    return
    end
    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
    end
    setmetatable(newdate, datemt)
    setmetatable(newdate, datemt)
    Line 1,073: Line 1,310:


    local function _diff_age(diff, code, options)
    local function _diff_age(diff, code, options)
    -- Return a tuple of values from diff as specified by code.
    -- Return a tuple of integer values from diff as specified by code, except that
    -- If options == 'duration', an extra day is added.
    -- each integer may be a list of two integers for a diff with a partial date.
    -- 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
    if not is_diff(diff) then
    local f = options == 'duration' and 'duration' or 'age'
    local f = wantduration and 'duration' or 'age'
    error(f .. ': need a date difference (use "diff:' .. f .. '()" with a colon)', 2)
    error(f .. ': need a date difference (use "diff:' .. f .. '()" with a colon)', 2)
    end
    end
    local extra_day = options == 'duration' and 1 or 0
    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
    -- Default: assume code == 'y'; ignore invalid codes.
    return choose(diff.partial.years)
    end
    local extra_days = wantduration and 1 or 0
    if code == 'wd' or code == 'w' or code == 'd' then
    if code == 'wd' or code == 'w' or code == 'd' then
    local d = diff.age_days + extra_day
    local offset = wantround and 0.5 or 0
    if code == 'd' then
    local days = diff.age_days + extra_days
    return d
    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 = diff.hours, diff.minutes
    if code == 'dh' or code == 'dhm' then
    local days = floor(diff.age_days + extra_days)
    local inc_hour
    if wantround then
    if code == 'dh' then
    if M >= 30 then
    inc_hour = true
    end
    elseif diff.seconds >= 30 then
    M = M + 1
    if M >= 60 then
    M = 0
    inc_hour = true
    end
    end
    if inc_hour then
    H = H + 1
    if H >= 24 then
    H = 0
    days = days + 1
    end
    end
    end
    if code == 'dh' then
    return days, H
    end
    return days, H, M
    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 diff.seconds >= 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
    end
    local w = floor(d / 7)
    if inc_hour then
    if code == 'w' then
    H = H + 1
    return w
    if H >= 24 then
    H = 0
    extra_days = extra_days + 1
    end
    end
    end
    return w, d % 7
    end
    end
    local y, m, d = diff.years, diff.months, diff.days
    local y, m, d = diff.years, diff.months, diff.days
    if extra_day > 0 then
    if extra_days > 0 then
    d = d + extra_day
    d = d + extra_days
    local to_date = diff.date1
    if d > 28 or code == 'yd' then
    if d > days_in_month(to_date.year, to_date.month, to_date.calendar) then
    -- Recalculate in case have passed a month.
    d = 1
    diff = diff.date1 + extra_days - diff.date2
    m = m + 1
    y, m, d = diff.years, diff.months, diff.days
    if m > 12 then
    m = 1
    y = y + 1
    end
    end
    end
    end
    end
    if code == 'ymd' then
    if code == 'ymd' then
    return y, m, d
    return y, m, d
    end
    elseif code == 'yd' then
    if code == 'ym' then
    if y > 0 then
    return y, m
    -- It is known that diff.date1 > diff.date2.
    end
    diff = diff.date1 - (diff.date2 + (y .. 'y'))
    if code == 'm' then
    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
    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
    end
    if code == 'ymwd' then
    -- Default: assume code == 'y'; ignore invalid codes.
    return y, m, floor(d / 7), d % 7
    if wantround and m >= 6 then
    y = y + 1
    end
    end
    return y -- default: assume code == 'y'; ignore invalid codes
    return y
    end
    end


    local function _diff_duration(diff, code)
    local function _diff_duration(diff, code, options)
    return _diff_age(diff, code, 'duration')
    if type(options) ~= 'table' then
    options = { round = options }
    end
    options.duration = true
    return _diff_age(diff, code, options)
    end
    end


    Line 1,134: Line 1,500:
    local value
    local value
    if key == 'age_days' then
    if key == 'age_days' then
    value = self.date1.jdz - self.date2.jdz
    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
    end
    if value ~= nil then
    if value ~= nil then
    Line 1,160: Line 1,533:
    end
    end
    local isnegative = false
    local isnegative = false
    local iszero = false
    if date1 < date2 then
    if date1 < date2 then
    isnegative = true
    isnegative = true
    date1, date2 = date2, date1
    date1, date2 = date2, date1
    elseif date1 == date2 then
    iszero = true
    end
    end
    -- It is known that date1 >= date2 (period is from date2 to date1).
    -- 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 y1, m1 = date1.year, date1.month
    local y2, m2 = date2.year, date2.month
    local y2, m2 = date2.year, date2.month
    Line 1,193: Line 1,610:
    date1 = date1,
    date1 = date1,
    date2 = date2,
    date2 = date2,
    partial = false,  -- avoid index lookup
    years = years,
    years = years,
    months = months,
    months = months,
    Line 1,200: Line 1,618:
    seconds = S,
    seconds = S,
    isnegative = isnegative,
    isnegative = isnegative,
    iszero = iszero,
    age = _diff_age,
    age = _diff_age,
    duration = _diff_duration,
    duration = _diff_duration,
    Retrieved from "https://nonbinary.wiki/wiki/Module:Date"