Jump to content

Module:Date: Difference between revisions

Module:Date (edit)

Revision as of 09:51, 29 February 2016

5,802 bytes added ,  8 years ago
formatted output and strftime
(enhanced version of Module:Age which will be replaced by this module as it provides generic date functions)
 
(formatted output and strftime)
Line 45: Line 45:
local function is_leap_year(year, calname)
local function is_leap_year(year, calname)
-- Return true if year is a leap year.
-- Return true if year is a leap year.
if calname == 'JCAL' then
if calname == 'Julian' then
return year % 4 == 0
return year % 4 == 0
end
end
Line 66: Line 66:
-- http://www.tondering.dk/claus/cal/julperiod.php#formula
-- http://www.tondering.dk/claus/cal/julperiod.php#formula
-- Testing shows this works for all dates from year -9999 to 9999!
-- Testing shows this works for all dates from year -9999 to 9999!
-- JDN 0 is the 24-hour period starting at noon UTC on
-- JDN 0 is the 24-hour period starting at noon UTC on Monday
--    1 January 4713 BC  = (-4712, 1, 1)  Julian calendar
--    1 January 4713 BC  = (-4712, 1, 1)  Julian calendar
--  24 November 4714 BC = (-4713, 11, 24) Gregorian calendar
--  24 November 4714 BC = (-4713, 11, 24) Gregorian calendar
Line 76: Line 76:
local a = floor((14 - date.month)/12)
local a = floor((14 - date.month)/12)
local y = date.year + 4800 - a
local y = date.year + 4800 - a
if date.calname == 'JCAL' then
if date.calname == 'Julian' then
offset = floor(y/4) - 32083
offset = floor(y/4) - 32083
else
else
Line 104: Line 104:
local jd = date.jd
local jd = date.jd
local limits  -- min/max limits for date ranges −9999-01-01 to 9999-12-31
local limits  -- min/max limits for date ranges −9999-01-01 to 9999-12-31
if calname == 'JCAL' then
if calname == 'Julian' then
limits = { -1931076.5, 5373557.5 }
limits = { -1931076.5, 5373557.49999 }
elseif calname == 'GCAL' then
elseif calname == 'Gregorian' then
limits = { -1930999.5, 5373484.5 }
limits = { -1930999.5, 5373484.49999 }
else
else
limits = { 1, 0 }  -- impossible
limits = { 1, 0 }  -- impossible
end
end
if not (limits[1] <= jd and jd < limits[2]) then
if not (limits[1] <= jd and jd <= limits[2]) then
date.isvalid = false
date.isvalid = false
return
return
Line 138: Line 138:
end
end
local b, c
local b, c
if calname == 'JCAL' then
if calname == 'Julian' then
b = 0
b = 0
c = jdn + 32082
c = jdn + 32082
Line 154: Line 154:
end
end


local function date_text(date)
local function make_option_table(options)
-- Return formatted string from given date.
-- If options is a string, return a table with its settings.
-- Otherwise return options (it should already be a table).
if type(options) == 'string' then
-- Example: 'am:AM era:BC'
local result = {}
for item in options:gmatch('%S+') do
local lhs, rhs = item:match('^(%w+):(.*)$')
if lhs then
result[lhs] = rhs
end
end
return result
end
return options
end
 
local function strftime(date, format, options)
-- Return date formatted as a string using codes similar to those
-- in the C strftime library function.
if not date.isvalid then
if not date.isvalid then
return '(invalid)'
return '(invalid)'
end
end
local time = ''
local codes = {
if date.hastime then
a = { field = 'dayabbr' },
if date.second > 0 then
A = { field = 'dayname' },
time = string.format(' %02d:%02d:%02d',
b = { field = 'monthabbr' },
date.hour,
B = { field = 'monthname' },
date.minute,
u = { fmt = '%d'  , field = 'dowiso' },
date.second
w = { fmt = '%d'  , field = 'dow' },
)
d = { fmt = '%02d', field = 'day' },
else
m = { fmt = '%02d', field = 'month' },
time = string.format(' %02d:%02d',
Y = { fmt = '%04d', field = 'year' },
date.hour,
H = { fmt = '%02d', field = 'hour' },
date.minute
M = { fmt = '%02d', field = 'minute' },
)
S = { fmt = '%02d', field = 'second' },
j = { fmt = '%03d', field = 'doy' },
I = { fmt = '%02d', field = 'hour', special = 'hour12' },
p = { field = 'hour', special = 'am' },
X = { fmt = '%02d:%02d:%02d', field = 'hour', special = 'hms' },
['-d'] = { fmt = '%d', field = 'day' },
['-m'] = { fmt = '%d', field = 'month' },
['-Y'] = { fmt = '%d', field = 'year' },
['-j'] = { fmt = '%d', field = 'doy' },
}
options = make_option_table(options or date.options)
local amopt = options.am
local eraopt = options.era
local function replace_code(id)
local code = codes[id]
if code then
local fmt = code.fmt
local value = date[code.field]
local special = code.special
if special then
if special == 'hour12' then
value = value % 12
value = value == 0 and 12 or value
elseif special == 'hms' then
return string.format(fmt, value, date.minute, date.second)
elseif special == 'am' then
local ap = ({
['a.m.'] = { 'a.m.', 'p.m.' },
['AM'] = { 'AM', 'PM' },
['A.M.'] = { 'A.M.', 'P.M.' },
})[amopt] or { 'am', 'pm' }
return value < 12 and ap[1] or ap[2]
end
end
if code.field == 'year' then
if eraopt == 'BCMINUS' or eraopt == 'BCNEGATIVE' then
local sign
if value >= 0 then
sign = ''
else
sign = eraopt == 'BCMINUS' and MINUS or '-'
value = -value
end
return sign .. string.format(fmt, value)
end
if value <= 0 then
value = 1 - value
end
end
return fmt and string.format(fmt, value) or value
end
end
end
end
local y = date.year
local function replace_property(id)
local sign = ''
local result = date[id]
if y < 0 then
if type(result) == 'string' then
sign = MINUS
if id == 'era' and result ~= '' then
y = -y
-- Assume era follows a date.
return '&nbsp;' .. result
end
return result
end
if type(result) == 'number' then
return tostring(result)
end
if type(result) == 'boolean' then
return result and '1' or '0'
end
-- This occurs, for example, if id is the name of a function.
return nil
end
end
return string.format('%s%04d-%02d-%02d%s',
local PERCENT = '\127PERCENT\127'
sign,
return (format
y,
:gsub('%%%%', PERCENT)
date.month,
:gsub('%%{(%w+)}', replace_property)
date.day,
:gsub('%%(-?%a)', replace_code)
time
:gsub(PERCENT, '%%')
)
)
end
end
local function date_text(date, fmt, options)
-- Return formatted string from given date.
if not (type(date) == 'table' and date.isvalid) then
return '(invalid)'
end
if type(fmt) ~= 'string' then
fmt = '%Y-%m-%d'
if date.hastime then
if date.second > 0 then
fmt = fmt .. ' %H:%M:%S'
else
fmt = fmt .. ' %H:%M'
end
end
return strftime(date, fmt, options or { era = 'BCMINUS' })
end
if fmt:find('%', 1, true) then
return strftime(date, fmt, options)
end
local t = collection()
for item in fmt:gmatch('%S+') do
local f
if item == 'hm' then
f = '%H:%M'
elseif item == 'hms' then
f = '%H:%M:%S'
elseif item == 'ymd' then
f = '%Y:%m:%d%{era}'
elseif item == 'mdy' then
f = '%B %-d, %Y%{era}'
elseif item == 'dmy' then
f = '%-d %B %Y%{era}'
else
return '(invalid format)'
end
t:add(f)
end
return strftime(date, t:join(' '), 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 month_number(text)
local function month_number(text)
Line 242: Line 388:
return nil
return nil
end
end
local era_text = {
-- options.era = { year<0  , year>0 }
['BCMINUS']    = { MINUS  , ''    },
['BCNEGATIVE'] = { '-'    , ''    },
['BC']        = { 'BC'    , ''    },
['B.C.']      = { 'B.C.'  , ''    },
['BCE']        = { 'BCE'  , ''    },
['B.C.E.']    = { 'B.C.E.', ''    },
['AD']        = { 'BC'    , 'AD'  },
['A.D.']      = { 'B.C.'  , 'A.D.' },
['CE']        = { 'BCE'  , 'CE'  },
['C.E.']      = { 'B.C.E.', 'C.E.' },
}


-- Metatable for some operations on dates.
-- Metatable for some operations on dates.
-- For Lua 5.1, __lt does not work if the metatable is an anonymous table.
-- For Lua 5.1, __lt does not work if the metatable is an anonymous table.
local Date  -- forward declaration
local datemt = {
local datemt = {
__eq = function (lhs, rhs)
__eq = function (lhs, rhs)
Line 263: Line 424:
__index = function (self, key)
__index = function (self, key)
local value
local value
if key == 'jd' or key == 'jdz' then
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.jd + 1) % 7  -- day-of-week 0=Sun to 6=Sat
elseif key == 'dowiso' then
value = (self.jd % 7) + 1  -- ISO day-of-week 1=Mon to 7=Sun
elseif key == 'doy' then
local first = Date(self.year, 1, 1, self.calname).jd
value = self.jd - first + 1  -- day-of-year 1 to 366
elseif key == 'era' then
-- Era text from year and options.
local eraopt = self.options.era
local sign
if self.year == 0 then
sign = (eraopt == 'BCMINUS' or eraopt == 'BCNEGATIVE') and 2 or 1
else
sign = self.year > 0 and 2 or 1
end
value = era_text[eraopt][sign]
elseif key == 'gsd' then
-- GSD = 1 from 00:00:00 to 23:59:59 on 1 January 1 AD Gregorian calendar,
-- which is JDN = 1721426, and is from jd 1721425.5 to 1721426.49999.
value = math.floor(self.jd - 1721424.5)
elseif key == 'jd' or key == 'jdz' then
local jd, jdz = julian_date(self)
local jd, jdz = julian_date(self)
rawset(self, 'jd', jd)
rawset(self, 'jd', jd)
rawset(self, 'jdz', jdz)
rawset(self, 'jdz', jdz)
return key == 'jd' and jd or jdz
return key == 'jd' and jd or jdz
elseif key == 'gsd' then
-- GSD = 1 from 00:00:00 to 23:59:59 on 1 January 1 AD Gregorian calendar,
-- which is JDN = 1721426, and is from jd 1721425.5 to 1721426.49999.
value = math.floor(self.jd - 1721424.5)
elseif key == 'is_leap_year' then
elseif key == 'is_leap_year' then
value = is_leap_year(self.year, self.calname)
value = is_leap_year(self.year, self.calname)
elseif key == 'monthabbr' then
value = month_info[self.month][1]
elseif key == 'monthname' then
value = month_info[self.month][2]
end
end
if value ~= nil then
if value ~= nil then
Line 294: Line 480:
Date('04:30:59 1 April 1995', 'julian')
Date('04:30:59 1 April 1995', 'julian')
]]
]]
local function Date(...)
function Date(...) -- for forward declaration above
-- Return a table to hold a date assuming a uniform calendar always applies (proleptic).
-- Return a table to hold a date assuming a uniform calendar always applies (proleptic).
-- If invalid, return an empty table which is regarded as invalid.
-- If invalid, return an empty table which is regarded as invalid.
local calendars = { julian = 'JCAL', Julian = 'JCAL', gregorian = 'GCAL', Gregorian = 'GCAL' }
local calendars = { julian = 'Julian', gregorian = 'Gregorian' }
local result = {
local result = {
isvalid = false,   -- false avoids __index lookup
isvalid = false, -- false avoids __index lookup
calname = 'GCAL',  -- default is Gregorian calendar
calname = 'Gregorian',  -- default is Gregorian calendar
hastime = false,   -- true if input sets a time
hastime = false, -- true if input sets a time
hour = 0,         -- always set hour/minute/second so don't have to handle nil
hour = 0, -- always set hour/minute/second so don't have to handle nil
minute = 0,
minute = 0,
second = 0,
second = 0,
Line 308: Line 494:
return days_in_month(self.year, month, self.calname)
return days_in_month(self.year, month, self.calname)
end,
end,
-- Valid option settings are:
-- am: 'am', 'a.m.', 'AM', 'A.M.'
-- era: 'BCMINUS', 'BCNEGATIVE', 'BC', 'B.C.', 'BCE', 'B.C.E.', 'AD', 'A.D.', 'CE', 'C.E.'
options = { am = 'am', era = 'BC' },
text = date_text,
text = date_text,
}
}
Line 315: Line 505:
for _, v in ipairs({...}) do
for _, v in ipairs({...}) do
v = strip_to_nil(v)
v = strip_to_nil(v)
local vlower = type(v) == 'string' and v:lower() or nil
if v == nil then
if v == nil then
-- Ignore empty arguments after stripping so modules can directly pass template parameters.
-- Ignore empty arguments after stripping so modules can directly pass template parameters.
elseif calendars[v] then
elseif calendars[vlower] then
result.calname = calendars[v]
result.calname = calendars[vlower]
else
else
local num = tonumber(v)
local num = tonumber(v)
Line 376: Line 567:
result.hastime = true
result.hastime = true
end
end
result.calname = 'GCAL'  -- ignore any given calendar name
result.calname = 'Gregorian'  -- ignore any given calendar name
result.isvalid = true
result.isvalid = true
elseif argtype == 'setdate' then
elseif argtype == 'setdate' then
Line 418: Line 609:
-- TODO Replace with something using Julian dates?
-- TODO Replace with something using Julian dates?
--      Who checks for isvalid()?
--      Who checks for isvalid()?
--      Handle calname == 'JCAL'
--      Handle calname == 'Julian'
local calname = 'GCAL'  -- TODO fix
local calname = 'Gregorian'  -- TODO fix
local isnegative
local isnegative
if date2 < date1 then
if date2 < date1 then
Anonymous user
Retrieved from "https://nonbinary.wiki/wiki/Special:MobileDiff/30255"
Cookies help us deliver our services. By using our services, you agree to our use of cookies.
More information