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ruby--ruby/lib/date.rb
tadf bf031c9699 * lib/date.rb, lib/date/format.rb: parse's hints as an 
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git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@15125 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
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#
# date.rb - date and time library
#
# Author: Tadayoshi Funaba 1998-2008
#
# Documentation: William Webber <william@williamwebber.com>
#
#--
# $Id: date.rb,v 2.37 2008-01-17 20:16:31+09 tadf Exp $
#++
#
# == Overview
#
# This file provides two classes for working with
# dates and times.
#
# The first class, Date, represents dates.
# It works with years, months, weeks, and days.
# See the Date class documentation for more details.
#
# The second, DateTime, extends Date to include hours,
# minutes, seconds, and fractions of a second. It
# provides basic support for time zones. See the
# DateTime class documentation for more details.
#
# === Ways of calculating the date.
#
# In common usage, the date is reckoned in years since or
# before the Common Era (CE/BCE, also known as AD/BC), then
# as a month and day-of-the-month within the current year.
# This is known as the *Civil* *Date*, and abbreviated
# as +civil+ in the Date class.
#
# Instead of year, month-of-the-year, and day-of-the-month,
# the date can also be reckoned in terms of year and
# day-of-the-year. This is known as the *Ordinal* *Date*,
# and is abbreviated as +ordinal+ in the Date class. (Note
# that referring to this as the Julian date is incorrect.)
#
# The date can also be reckoned in terms of year, week-of-the-year,
# and day-of-the-week. This is known as the *Commercial*
# *Date*, and is abbreviated as +commercial+ in the
# Date class. The commercial week runs Monday (day-of-the-week
# 1) to Sunday (day-of-the-week 7), in contrast to the civil
# week which runs Sunday (day-of-the-week 0) to Saturday
# (day-of-the-week 6). The first week of the commercial year
# starts on the Monday on or before January 1, and the commercial
# year itself starts on this Monday, not January 1.
#
# For scientific purposes, it is convenient to refer to a date
# simply as a day count, counting from an arbitrary initial
# day. The date first chosen for this was January 1, 4713 BCE.
# A count of days from this date is the *Julian* *Day* *Number*
# or *Julian* *Date*, which is abbreviated as +jd+ in the
# Date class. This is in local time, and counts from midnight
# on the initial day. The stricter usage is in UTC, and counts
# from midday on the initial day. This is referred to in the
# Date class as the *Astronomical* *Julian* *Day* *Number*, and
# abbreviated as +ajd+. In the Date class, the Astronomical
# Julian Day Number includes fractional days.
#
# Another absolute day count is the *Modified* *Julian* *Day*
# *Number*, which takes November 17, 1858 as its initial day.
# This is abbreviated as +mjd+ in the Date class. There
# is also an *Astronomical* *Modified* *Julian* *Day* *Number*,
# which is in UTC and includes fractional days. This is
# abbreviated as +amjd+ in the Date class. Like the Modified
# Julian Day Number (and unlike the Astronomical Julian
# Day Number), it counts from midnight.
#
# Alternative calendars such as the Chinese Lunar Calendar,
# the Islamic Calendar, or the French Revolutionary Calendar
# are not supported by the Date class; nor are calendars that
# are based on an Era different from the Common Era, such as
# the Japanese Imperial Calendar or the Republic of China
# Calendar.
#
# === Calendar Reform
#
# The standard civil year is 365 days long. However, the
# solar year is fractionally longer than this. To account
# for this, a *leap* *year* is occasionally inserted. This
# is a year with 366 days, the extra day falling on February 29.
# In the early days of the civil calendar, every fourth
# year without exception was a leap year. This way of
# reckoning leap years is the *Julian* *Calendar*.
#
# However, the solar year is marginally shorter than 365 1/4
# days, and so the *Julian* *Calendar* gradually ran slow
# over the centuries. To correct this, every 100th year
# (but not every 400th year) was excluded as a leap year.
# This way of reckoning leap years, which we use today, is
# the *Gregorian* *Calendar*.
#
# The Gregorian Calendar was introduced at different times
# in different regions. The day on which it was introduced
# for a particular region is the *Day* *of* *Calendar*
# *Reform* for that region. This is abbreviated as +sg+
# (for Start of Gregorian calendar) in the Date class.
#
# Two such days are of particular
# significance. The first is October 15, 1582, which was
# the Day of Calendar Reform for Italy and most Catholic
# countries. The second is September 14, 1752, which was
# the Day of Calendar Reform for England and its colonies
# (including what is now the United States). These two
# dates are available as the constants Date::ITALY and
# Date::ENGLAND, respectively. (By comparison, Germany and
# Holland, less Catholic than Italy but less stubborn than
# England, changed over in 1698; Sweden in 1753; Russia not
# till 1918, after the Revolution; and Greece in 1923. Many
# Orthodox churches still use the Julian Calendar. A complete
# list of Days of Calendar Reform can be found at
# http://www.polysyllabic.com/GregConv.html.)
#
# Switching from the Julian to the Gregorian calendar
# involved skipping a number of days to make up for the
# accumulated lag, and the later the switch was (or is)
# done, the more days need to be skipped. So in 1582 in Italy,
# 4th October was followed by 15th October, skipping 10 days; in 1752
# in England, 2nd September was followed by 14th September, skipping
# 11 days; and if I decided to switch from Julian to Gregorian
# Calendar this midnight, I would go from 27th July 2003 (Julian)
# today to 10th August 2003 (Gregorian) tomorrow, skipping
# 13 days. The Date class is aware of this gap, and a supposed
# date that would fall in the middle of it is regarded as invalid.
#
# The Day of Calendar Reform is relevant to all date representations
# involving years. It is not relevant to the Julian Day Numbers,
# except for converting between them and year-based representations.
#
# In the Date and DateTime classes, the Day of Calendar Reform or
# +sg+ can be specified a number of ways. First, it can be as
# the Julian Day Number of the Day of Calendar Reform. Second,
# it can be using the constants Date::ITALY or Date::ENGLAND; these
# are in fact the Julian Day Numbers of the Day of Calendar Reform
# of the respective regions. Third, it can be as the constant
# Date::JULIAN, which means to always use the Julian Calendar.
# Finally, it can be as the constant Date::GREGORIAN, which means
# to always use the Gregorian Calendar.
#
# Note: in the Julian Calendar, New Years Day was March 25. The
# Date class does not follow this convention.
#
# === Time Zones
#
# DateTime objects support a simple representation
# of time zones. Time zones are represented as an offset
# from UTC, as a fraction of a day. This offset is the
# how much local time is later (or earlier) than UTC.
# UTC offset 0 is centred on England (also known as GMT).
# As you travel east, the offset increases until you
# reach the dateline in the middle of the Pacific Ocean;
# as you travel west, the offset decreases. This offset
# is abbreviated as +of+ in the Date class.
#
# This simple representation of time zones does not take
# into account the common practice of Daylight Savings
# Time or Summer Time.
#
# Most DateTime methods return the date and the
# time in local time. The two exceptions are
# #ajd() and #amjd(), which return the date and time
# in UTC time, including fractional days.
#
# The Date class does not support time zone offsets, in that
# there is no way to create a Date object with a time zone.
# However, methods of the Date class when used by a
# DateTime instance will use the time zone offset of this
# instance.
#
# == Examples of use
#
# === Print out the date of every Sunday between two dates.
#
# def print_sundays(d1, d2)
# d1 +=1 while (d1.wday != 0)
# d1.step(d2, 7) do |date|
# puts "#{Date::MONTHNAMES[date.mon]} #{date.day}"
# end
# end
#
# print_sundays(Date::civil(2003, 4, 8), Date::civil(2003, 5, 23))
#
# === Calculate how many seconds to go till midnight on New Year's Day.
#
# def secs_to_new_year(now = DateTime::now())
# new_year = DateTime.new(now.year + 1, 1, 1)
# dif = new_year - now
# hours, mins, secs, ignore_fractions = Date::day_fraction_to_time(dif)
# return hours * 60 * 60 + mins * 60 + secs
# end
#
# puts secs_to_new_year()
require 'rational'
require 'date/format'
# Class representing a date.
#
# See the documentation to the file date.rb for an overview.
#
# Internally, the date is represented as an Astronomical
# Julian Day Number, +ajd+. The Day of Calendar Reform, +sg+, is
# also stored, for conversions to other date formats. (There
# is also an +of+ field for a time zone offset, but this
# is only for the use of the DateTime subclass.)
#
# A new Date object is created using one of the object creation
# class methods named after the corresponding date format, and the
# arguments appropriate to that date format; for instance,
# Date::civil() (aliased to Date::new()) with year, month,
# and day-of-month, or Date::ordinal() with year and day-of-year.
# All of these object creation class methods also take the
# Day of Calendar Reform as an optional argument.
#
# Date objects are immutable once created.
#
# Once a Date has been created, date values
# can be retrieved for the different date formats supported
# using instance methods. For instance, #mon() gives the
# Civil month, #cwday() gives the Commercial day of the week,
# and #yday() gives the Ordinal day of the year. Date values
# can be retrieved in any format, regardless of what format
# was used to create the Date instance.
#
# The Date class includes the Comparable module, allowing
# date objects to be compared and sorted, ranges of dates
# to be created, and so forth.
class Date
include Comparable
# Full month names, in English. Months count from 1 to 12; a
# month's numerical representation indexed into this array
# gives the name of that month (hence the first element is nil).
MONTHNAMES = [nil] + %w(January February March April May June July
August September October November December)
# Full names of days of the week, in English. Days of the week
# count from 0 to 6 (except in the commercial week); a day's numerical
# representation indexed into this array gives the name of that day.
DAYNAMES = %w(Sunday Monday Tuesday Wednesday Thursday Friday Saturday)
# Abbreviated month names, in English.
ABBR_MONTHNAMES = [nil] + %w(Jan Feb Mar Apr May Jun
Jul Aug Sep Oct Nov Dec)
# Abbreviated day names, in English.
ABBR_DAYNAMES = %w(Sun Mon Tue Wed Thu Fri Sat)
[MONTHNAMES, DAYNAMES, ABBR_MONTHNAMES, ABBR_DAYNAMES].each do |xs|
xs.each{|x| x.freeze unless x.nil?}.freeze
end
class Infinity < Numeric # :nodoc:
include Comparable
def initialize(d=1) @d = d <=> 0 end
def d() @d end
protected :d
def zero? () false end
def finite? () false end
def infinite? () d.nonzero? end
def nan? () d.zero? end
def abs() self.class.new end
def -@ () self.class.new(-d) end
def +@ () self.class.new(+d) end
def <=> (other)
case other
when Infinity; return d <=> other.d
when Numeric; return d
else
begin
l, r = other.coerce(self)
return l <=> r
rescue NoMethodError
end
end
nil
end
def coerce(other)
case other
when Numeric; return -d, d
else
super
end
end
end
# The Julian Day Number of the Day of Calendar Reform for Italy
# and the Catholic countries.
ITALY = 2299161 # 1582-10-15
# The Julian Day Number of the Day of Calendar Reform for England
# and her Colonies.
ENGLAND = 2361222 # 1752-09-14
# A constant used to indicate that a Date should always use the
# Julian calendar.
JULIAN = Infinity.new
# A constant used to indicate that a Date should always use the
# Gregorian calendar.
GREGORIAN = -Infinity.new
HALF_DAYS_IN_DAY = Rational(1, 2) # :nodoc:
HOURS_IN_DAY = Rational(1, 24) # :nodoc:
MINUTES_IN_DAY = Rational(1, 1440) # :nodoc:
SECONDS_IN_DAY = Rational(1, 86400) # :nodoc:
MILLISECONDS_IN_DAY = Rational(1, 86400*10**3) # :nodoc:
NANOSECONDS_IN_DAY = Rational(1, 86400*10**9) # :nodoc:
MILLISECONDS_IN_SECOND = Rational(1, 10**3) # :nodoc:
NANOSECONDS_IN_SECOND = Rational(1, 10**9) # :nodoc:
MJD_EPOCH_IN_AJD = Rational(4800001, 2) # 1858-11-17 # :nodoc:
UNIX_EPOCH_IN_AJD = Rational(4881175, 2) # 1970-01-01 # :nodoc:
MJD_EPOCH_IN_CJD = 2400001 # :nodoc:
UNIX_EPOCH_IN_CJD = 2440588 # :nodoc:
LD_EPOCH_IN_CJD = 2299160 # :nodoc:
t = Module.new do
private
def find_fdoy(y, sg) # :nodoc:
j = nil
1.upto(31) do |d|
break if j = _valid_civil?(y, 1, d, sg)
end
j
end
def find_ldoy(y, sg) # :nodoc:
j = nil
31.downto(1) do |d|
break if j = _valid_civil?(y, 12, d, sg)
end
j
end
def find_fdom(y, m, sg) # :nodoc:
j = nil
1.upto(31) do |d|
break if j = _valid_civil?(y, m, d, sg)
end
j
end
def find_ldom(y, m, sg) # :nodoc:
j = nil
31.downto(1) do |d|
break if j = _valid_civil?(y, m, d, sg)
end
j
end
# Convert an Ordinal Date to a Julian Day Number.
#
# +y+ and +d+ are the year and day-of-year to convert.
# +sg+ specifies the Day of Calendar Reform.
#
# Returns the corresponding Julian Day Number.
def ordinal_to_jd(y, d, sg=GREGORIAN) # :nodoc:
find_fdoy(y, sg) + d - 1
end
# Convert a Julian Day Number to an Ordinal Date.
#
# +jd+ is the Julian Day Number to convert.
# +sg+ specifies the Day of Calendar Reform.
#
# Returns the corresponding Ordinal Date as
# [year, day_of_year]
def jd_to_ordinal(jd, sg=GREGORIAN) # :nodoc:
y = jd_to_civil(jd, sg)[0]
j = find_fdoy(y, sg)
doy = jd - j + 1
return y, doy
end
# Convert a Civil Date to a Julian Day Number.
# +y+, +m+, and +d+ are the year, month, and day of the
# month. +sg+ specifies the Day of Calendar Reform.
#
# Returns the corresponding Julian Day Number.
def civil_to_jd(y, m, d, sg=GREGORIAN) # :nodoc:
if m <= 2
y -= 1
m += 12
end
a = (y / 100.0).floor
b = 2 - a + (a / 4.0).floor
jd = (365.25 * (y + 4716)).floor +
(30.6001 * (m + 1)).floor +
d + b - 1524
if jd < sg
jd -= b
end
jd
end
# Convert a Julian Day Number to a Civil Date. +jd+ is
# the Julian Day Number. +sg+ specifies the Day of
# Calendar Reform.
#
# Returns the corresponding [year, month, day_of_month]
# as a three-element array.
def jd_to_civil(jd, sg=GREGORIAN) # :nodoc:
if jd < sg
a = jd
else
x = ((jd - 1867216.25) / 36524.25).floor
a = jd + 1 + x - (x / 4.0).floor
end
b = a + 1524
c = ((b - 122.1) / 365.25).floor
d = (365.25 * c).floor
e = ((b - d) / 30.6001).floor
dom = b - d - (30.6001 * e).floor
if e <= 13
m = e - 1
y = c - 4716
else
m = e - 13
y = c - 4715
end
return y, m, dom
end
# Convert a Commercial Date to a Julian Day Number.
#
# +y+, +w+, and +d+ are the (commercial) year, week of the year,
# and day of the week of the Commercial Date to convert.
# +sg+ specifies the Day of Calendar Reform.
def commercial_to_jd(y, w, d, sg=GREGORIAN) # :nodoc:
j = find_fdoy(y, sg) + 3
(j - (((j - 1) + 1) % 7)) +
7 * (w - 1) +
(d - 1)
end
# Convert a Julian Day Number to a Commercial Date
#
# +jd+ is the Julian Day Number to convert.
# +sg+ specifies the Day of Calendar Reform.
#
# Returns the corresponding Commercial Date as
# [commercial_year, week_of_year, day_of_week]
def jd_to_commercial(jd, sg=GREGORIAN) # :nodoc:
a = jd_to_civil(jd - 3, sg)[0]
y = if jd >= commercial_to_jd(a + 1, 1, 1, sg) then a + 1 else a end
w = 1 + ((jd - commercial_to_jd(y, 1, 1, sg)) / 7).floor
d = (jd + 1) % 7
d = 7 if d == 0
return y, w, d
end
def weeknum_to_jd(y, w, d, f=0, sg=GREGORIAN) # :nodoc:
a = find_fdoy(y, sg) + 6
(a - ((a - f) + 1) % 7 - 7) + 7 * w + d
end
def jd_to_weeknum(jd, f=0, sg=GREGORIAN) # :nodoc:
y, m, d = jd_to_civil(jd, sg)
a = find_fdoy(y, sg) + 6
w, d = (jd - (a - ((a - f) + 1) % 7) + 7).divmod(7)
return y, w, d
end
def nth_kday_to_jd(y, m, n, k, sg=GREGORIAN) # :nodoc:
j = if n > 0
find_fdom(y, m, sg) - 1
else
find_ldom(y, m, sg) + 7
end
(j - (((j - k) + 1) % 7)) + 7 * n
end
def jd_to_nth_kday(jd, sg=GREGORIAN) # :nodoc:
y, m, d = jd_to_civil(jd, sg)
j = find_fdom(y, m, sg)
return y, m, ((jd - j) / 7).floor + 1, jd_to_wday(jd)
end
# Convert an Astronomical Julian Day Number to a (civil) Julian
# Day Number.
#
# +ajd+ is the Astronomical Julian Day Number to convert.
# +of+ is the offset from UTC as a fraction of a day (defaults to 0).
#
# Returns the (civil) Julian Day Number as [day_number,
# fraction] where +fraction+ is always 1/2.
def ajd_to_jd(ajd, of=0) (ajd + of + HALF_DAYS_IN_DAY).divmod(1) end # :nodoc:
# Convert a (civil) Julian Day Number to an Astronomical Julian
# Day Number.
#
# +jd+ is the Julian Day Number to convert, and +fr+ is a
# fractional day.
# +of+ is the offset from UTC as a fraction of a day (defaults to 0).
#
# Returns the Astronomical Julian Day Number as a single
# numeric value.
def jd_to_ajd(jd, fr, of=0) jd + fr - of - HALF_DAYS_IN_DAY end # :nodoc:
# Convert a fractional day +fr+ to [hours, minutes, seconds,
# fraction_of_a_second]
def day_fraction_to_time(fr) # :nodoc:
ss, fr = fr.divmod(SECONDS_IN_DAY) # 4p
h, ss = ss.divmod(3600)
min, s = ss.divmod(60)
return h, min, s, fr * 86400
end
# Convert an +h+ hour, +min+ minutes, +s+ seconds period
# to a fractional day.
begin
Rational(Rational(1, 2), 2) # a challenge
def time_to_day_fraction(h, min, s)
Rational(h * 3600 + min * 60 + s, 86400) # 4p
end
rescue
def time_to_day_fraction(h, min, s)
if Integer === h && Integer === min && Integer === s
Rational(h * 3600 + min * 60 + s, 86400) # 4p
else
(h * 3600 + min * 60 + s).to_r/86400 # 4p
end
end
end
# Convert an Astronomical Modified Julian Day Number to an
# Astronomical Julian Day Number.
def amjd_to_ajd(amjd) amjd + MJD_EPOCH_IN_AJD end # :nodoc:
# Convert an Astronomical Julian Day Number to an
# Astronomical Modified Julian Day Number.
def ajd_to_amjd(ajd) ajd - MJD_EPOCH_IN_AJD end # :nodoc:
# Convert a Modified Julian Day Number to a Julian
# Day Number.
def mjd_to_jd(mjd) mjd + MJD_EPOCH_IN_CJD end # :nodoc:
# Convert a Julian Day Number to a Modified Julian Day
# Number.
def jd_to_mjd(jd) jd - MJD_EPOCH_IN_CJD end # :nodoc:
# Convert a count of the number of days since the adoption
# of the Gregorian Calendar (in Italy) to a Julian Day Number.
def ld_to_jd(ld) ld + LD_EPOCH_IN_CJD end # :nodoc:
# Convert a Julian Day Number to the number of days since
# the adoption of the Gregorian Calendar (in Italy).
def jd_to_ld(jd) jd - LD_EPOCH_IN_CJD end # :nodoc:
# Convert a Julian Day Number to the day of the week.
#
# Sunday is day-of-week 0; Saturday is day-of-week 6.
def jd_to_wday(jd) (jd + 1) % 7 end # :nodoc:
# Is +jd+ a valid Julian Day Number?
#
# If it is, returns it. In fact, any value is treated as a valid
# Julian Day Number.
def _valid_jd? (jd, sg=GREGORIAN) jd end # :nodoc:
# Do the year +y+ and day-of-year +d+ make a valid Ordinal Date?
# Returns the corresponding Julian Day Number if they do, or
# nil if they don't.
#
# +d+ can be a negative number, in which case it counts backwards
# from the end of the year (-1 being the last day of the year).
# No year wraparound is performed, however, so valid values of
# +d+ are -365 .. -1, 1 .. 365 on a non-leap-year,
# -366 .. -1, 1 .. 366 on a leap year.
# A date falling in the period skipped in the Day of Calendar Reform
# adjustment is not valid.
#
# +sg+ specifies the Day of Calendar Reform.
def _valid_ordinal? (y, d, sg=GREGORIAN) # :nodoc:
if d < 0
j = find_ldoy(y, sg)
ny, nd = jd_to_ordinal(j + d + 1, sg)
return unless ny == y
d = nd
end
jd = ordinal_to_jd(y, d, sg)
return unless [y, d] == jd_to_ordinal(jd, sg)
jd
end
# Do year +y+, month +m+, and day-of-month +d+ make a
# valid Civil Date? Returns the corresponding Julian
# Day Number if they do, nil if they don't.
#
# +m+ and +d+ can be negative, in which case they count
# backwards from the end of the year and the end of the
# month respectively. No wraparound is performed, however,
# and invalid values cause an ArgumentError to be raised.
# A date falling in the period skipped in the Day of Calendar
# Reform adjustment is not valid.
#
# +sg+ specifies the Day of Calendar Reform.
def _valid_civil? (y, m, d, sg=GREGORIAN) # :nodoc:
if m < 0
m += 13
end
if d < 0
j = find_ldom(y, m, sg)
ny, nm, nd = jd_to_civil(j + d + 1, sg)
return unless [ny, nm] == [y, m]
d = nd
end
jd = civil_to_jd(y, m, d, sg)
return unless [y, m, d] == jd_to_civil(jd, sg)
jd
end
# Do year +y+, week-of-year +w+, and day-of-week +d+ make a
# valid Commercial Date? Returns the corresponding Julian
# Day Number if they do, nil if they don't.
#
# Monday is day-of-week 1; Sunday is day-of-week 7.
#
# +w+ and +d+ can be negative, in which case they count
# backwards from the end of the year and the end of the
# week respectively. No wraparound is performed, however,
# and invalid values cause an ArgumentError to be raised.
# A date falling in the period skipped in the Day of Calendar
# Reform adjustment is not valid.
#
# +sg+ specifies the Day of Calendar Reform.
def _valid_commercial? (y, w, d, sg=GREGORIAN) # :nodoc:
if d < 0
d += 8
end
if w < 0
ny, nw, nd =
jd_to_commercial(commercial_to_jd(y + 1, 1, 1, sg) + w * 7, sg)
return unless ny == y
w = nw
end
jd = commercial_to_jd(y, w, d, sg)
return unless [y, w, d] == jd_to_commercial(jd, sg)
jd
end
def _valid_weeknum? (y, w, d, f, sg=GREGORIAN) # :nodoc:
if d < 0
d += 7
end
if w < 0
ny, nw, nd, nf =
jd_to_weeknum(weeknum_to_jd(y + 1, 1, f, f, sg) + w * 7, f, sg)
return unless ny == y
w = nw
end
jd = weeknum_to_jd(y, w, d, f, sg)
return unless [y, w, d] == jd_to_weeknum(jd, f, sg)
jd
end
def _valid_nth_kday? (y, m, n, k, sg=GREGORIAN) # :nodoc:
if k < 0
k += 7
end
if n < 0
ny, nm = (y * 12 + m).divmod(12)
nm, = (nm + 1) .divmod(1)
ny, nm, nn, nk =
jd_to_nth_kday(nth_kday_to_jd(ny, nm, 1, k, sg) + n * 7, sg)
return unless [ny, nm] == [y, m]
n = nn
end
jd = nth_kday_to_jd(y, m, n, k, sg)
return unless [y, m, n, k] == jd_to_nth_kday(jd, sg)
jd
end
# Do hour +h+, minute +min+, and second +s+ constitute a valid time?
#
# If they do, returns their value as a fraction of a day. If not,
# returns nil.
#
# The 24-hour clock is used. Negative values of +h+, +min+, and
# +sec+ are treating as counting backwards from the end of the
# next larger unit (e.g. a +min+ of -2 is treated as 58). No
# wraparound is performed.
def _valid_time? (h, min, s) # :nodoc:
h += 24 if h < 0
min += 60 if min < 0
s += 60 if s < 0
return unless ((0...24) === h &&
(0...60) === min &&
(0...60) === s) ||
(24 == h &&
0 == min &&
0 == s)
time_to_day_fraction(h, min, s)
end
end
extend t
include t
# Is a year a leap year in the Julian calendar?
#
# All years divisible by 4 are leap years in the Julian calendar.
def self.julian_leap? (y) y % 4 == 0 end
# Is a year a leap year in the Gregorian calendar?
#
# All years divisible by 4 are leap years in the Gregorian calendar,
# except for years divisible by 100 and not by 400.
def self.gregorian_leap? (y) y % 4 == 0 && y % 100 != 0 || y % 400 == 0 end
class << self; alias_method :leap?, :gregorian_leap? end
class << self; alias_method :new!, :new end
def self.valid_jd? (jd, sg=ITALY)
!!_valid_jd?(jd, sg)
end
def self.valid_ordinal? (y, d, sg=ITALY)
!!_valid_ordinal?(y, d, sg)
end
def self.valid_civil? (y, m, d, sg=ITALY)
!!_valid_civil?(y, m, d, sg)
end
class << self; alias_method :valid_date?, :valid_civil? end
def self.valid_commercial? (y, w, d, sg=ITALY)
!!_valid_commercial?(y, w, d, sg)
end
def self.valid_weeknum? (y, w, d, f, sg=ITALY) # :nodoc:
!!_valid_weeknum?(y, w, d, f, sg)
end
private_class_method :valid_weeknum?
def self.valid_nth_kday? (y, m, n, k, sg=ITALY) # :nodoc:
!!_valid_nth_kday?(y, m, n, k, sg)
end
private_class_method :valid_nth_kday?
def self.valid_time? (h, min, s) # :nodoc:
!!_valid_time?(h, min, s)
end
private_class_method :valid_time?
# Create a new Date object from a Julian Day Number.
#
# +jd+ is the Julian Day Number; if not specified, it defaults to
# 0.
# +sg+ specifies the Day of Calendar Reform.
def self.jd(jd=0, sg=ITALY)
jd = _valid_jd?(jd, sg)
new!(jd_to_ajd(jd, 0, 0), 0, sg)
end
# Create a new Date object from an Ordinal Date, specified
# by year +y+ and day-of-year +d+. +d+ can be negative,
# in which it counts backwards from the end of the year.
# No year wraparound is performed, however. An invalid
# value for +d+ results in an ArgumentError being raised.
#
# +y+ defaults to -4712, and +d+ to 1; this is Julian Day
# Number day 0.
#
# +sg+ specifies the Day of Calendar Reform.
def self.ordinal(y=-4712, d=1, sg=ITALY)
unless jd = _valid_ordinal?(y, d, sg)
raise ArgumentError, 'invalid date'
end
new!(jd_to_ajd(jd, 0, 0), 0, sg)
end
# Create a new Date object for the Civil Date specified by
# year +y+, month +m+, and day-of-month +d+.
#
# +m+ and +d+ can be negative, in which case they count
# backwards from the end of the year and the end of the
# month respectively. No wraparound is performed, however,
# and invalid values cause an ArgumentError to be raised.
# can be negative
#
# +y+ defaults to -4712, +m+ to 1, and +d+ to 1; this is
# Julian Day Number day 0.
#
# +sg+ specifies the Day of Calendar Reform.
def self.civil(y=-4712, m=1, d=1, sg=ITALY)
unless jd = _valid_civil?(y, m, d, sg)
raise ArgumentError, 'invalid date'
end
new!(jd_to_ajd(jd, 0, 0), 0, sg)
end
class << self; alias_method :new, :civil end
# Create a new Date object for the Commercial Date specified by
# year +y+, week-of-year +w+, and day-of-week +d+.
#
# Monday is day-of-week 1; Sunday is day-of-week 7.
#
# +w+ and +d+ can be negative, in which case they count
# backwards from the end of the year and the end of the
# week respectively. No wraparound is performed, however,
# and invalid values cause an ArgumentError to be raised.
#
# +y+ defaults to -4712, +w+ to 1, and +d+ to 1; this is
# Julian Day Number day 0.
#
# +sg+ specifies the Day of Calendar Reform.
def self.commercial(y=-4712, w=1, d=1, sg=ITALY)
unless jd = _valid_commercial?(y, w, d, sg)
raise ArgumentError, 'invalid date'
end
new!(jd_to_ajd(jd, 0, 0), 0, sg)
end
def self.weeknum(y=-4712, w=0, d=1, f=0, sg=ITALY)
unless jd = _valid_weeknum?(y, w, d, f, sg)
raise ArgumentError, 'invalid date'
end
new!(jd_to_ajd(jd, 0, 0), 0, sg)
end
private_class_method :weeknum
def self.nth_kday(y=-4712, m=1, n=1, k=1, sg=ITALY)
unless jd = _valid_nth_kday?(y, m, n, k, sg)
raise ArgumentError, 'invalid date'
end
new!(jd_to_ajd(jd, 0, 0), 0, sg)
end
private_class_method :nth_kday
def self.rewrite_frags(elem) # :nodoc:
elem ||= {}
if seconds = elem[:seconds]
d, fr = seconds.divmod(86400)
h, fr = fr.divmod(3600)
min, fr = fr.divmod(60)
s, fr = fr.divmod(1)
elem[:jd] = UNIX_EPOCH_IN_CJD + d
elem[:hour] = h
elem[:min] = min
elem[:sec] = s
elem[:sec_fraction] = fr
elem.delete(:seconds)
elem.delete(:offset)
end
elem
end
private_class_method :rewrite_frags
def self.complete_frags(elem) # :nodoc:
i = 0
g = [[:time, [:hour, :min, :sec]],
[nil, [:jd]],
[:ordinal, [:year, :yday, :hour, :min, :sec]],
[:civil, [:year, :mon, :mday, :hour, :min, :sec]],
[:commercial, [:cwyear, :cweek, :cwday, :hour, :min, :sec]],
[:wday, [:wday, :hour, :min, :sec]],
[:wnum0, [:year, :wnum0, :wday, :hour, :min, :sec]],
[:wnum1, [:year, :wnum1, :wday, :hour, :min, :sec]],
[nil, [:cwyear, :cweek, :wday, :hour, :min, :sec]],
[nil, [:year, :wnum0, :cwday, :hour, :min, :sec]],
[nil, [:year, :wnum1, :cwday, :hour, :min, :sec]]].
collect{|k, a| e = elem.values_at(*a).compact; [k, a, e]}.
select{|k, a, e| e.size > 0}.
sort_by{|k, a, e| [e.size, i -= 1]}.last
d = nil
if g && g[0] && (g[1].size - g[2].size) != 0
d ||= Date.today
case g[0]
when :ordinal
elem[:year] ||= d.year
elem[:yday] ||= 1
when :civil
g[1].each do |e|
break if elem[e]
elem[e] = d.__send__(e)
end
elem[:mon] ||= 1
elem[:mday] ||= 1
when :commercial
g[1].each do |e|
break if elem[e]
elem[e] = d.__send__(e)
end
elem[:cweek] ||= 1
elem[:cwday] ||= 1
when :wday
elem[:jd] ||= (d - d.wday + elem[:wday]).jd
when :wnum0
g[1].each do |e|
break if elem[e]
elem[e] = d.__send__(e)
end
elem[:wnum0] ||= 0
elem[:wday] ||= 0
when :wnum1
g[1].each do |e|
break if elem[e]
elem[e] = d.__send__(e)
end
elem[:wnum1] ||= 0
elem[:wday] ||= 0
end
end
if g && g[0] == :time
if self <= DateTime
d ||= Date.today
elem[:jd] ||= d.jd
end
end
elem[:hour] ||= 0
elem[:min] ||= 0
elem[:sec] ||= 0
elem[:sec] = [elem[:sec], 59].min
elem
end
private_class_method :complete_frags
def self.valid_date_frags?(elem, sg) # :nodoc:
catch :jd do
a = elem.values_at(:jd)
if a.all?
if jd = _valid_jd?(*(a << sg))
throw :jd, jd
end
end
a = elem.values_at(:year, :yday)
if a.all?
if jd = _valid_ordinal?(*(a << sg))
throw :jd, jd
end
end
a = elem.values_at(:year, :mon, :mday)
if a.all?
if jd = _valid_civil?(*(a << sg))
throw :jd, jd
end
end
a = elem.values_at(:cwyear, :cweek, :cwday)
if a[2].nil? && elem[:wday]
a[2] = elem[:wday].nonzero? || 7
end
if a.all?
if jd = _valid_commercial?(*(a << sg))
throw :jd, jd
end
end
a = elem.values_at(:year, :wnum0, :wday)
if a[2].nil? && elem[:cwday]
a[2] = elem[:cwday] % 7
end
if a.all?
if jd = _valid_weeknum?(*(a << 0 << sg))
throw :jd, jd
end
end
a = elem.values_at(:year, :wnum1, :wday)
if a[2]
a[2] = (a[2] - 1) % 7
end
if a[2].nil? && elem[:cwday]
a[2] = (elem[:cwday] - 1) % 7
end
if a.all?
if jd = _valid_weeknum?(*(a << 1 << sg))
throw :jd, jd
end
end
end
end
private_class_method :valid_date_frags?
def self.valid_time_frags? (elem) # :nodoc:
h, min, s = elem.values_at(:hour, :min, :sec)
_valid_time?(h, min, s)
end
private_class_method :valid_time_frags?
def self.new_by_frags(elem, sg) # :nodoc:
elem = rewrite_frags(elem)
elem = complete_frags(elem)
unless jd = valid_date_frags?(elem, sg)
raise ArgumentError, 'invalid date'
end
new!(jd_to_ajd(jd, 0, 0), 0, sg)
end
private_class_method :new_by_frags
# Create a new Date object by parsing from a String
# according to a specified format.
#
# +str+ is a String holding a date representation.
# +fmt+ is the format that the date is in. See
# date/format.rb for details on supported formats.
#
# The default +str+ is '-4712-01-01', and the default
# +fmt+ is '%F', which means Year-Month-Day_of_Month.
# This gives Julian Day Number day 0.
#
# +sg+ specifies the Day of Calendar Reform.
#
# An ArgumentError will be raised if +str+ cannot be
# parsed.
def self.strptime(str='-4712-01-01', fmt='%F', sg=ITALY)
elem = _strptime(str, fmt)
new_by_frags(elem, sg)
end
# Create a new Date object by parsing from a String,
# without specifying the format.
#
# +str+ is a String holding a date representation.
# +comp+ specifies whether to interpret 2-digit years
# as 19XX (>= 69) or 20XX (< 69); the default is not to.
# The method will attempt to parse a date from the String
# using various heuristics; see #_parse in date/format.rb
# for more details. If parsing fails, an ArgumentError
# will be raised.
#
# The default +str+ is '-4712-01-01'; this is Julian
# Day Number day 0.
#
# +sg+ specifies the Day of Calendar Reform.
def self.parse(str='-4712-01-01', comp=true, sg=ITALY)
elem = _parse(str, comp)
new_by_frags(elem, sg)
end
def self.iso8601(str='-4712-01-01', sg=ITALY) # :nodoc:
elem = _iso8601(str)
new_by_frags(elem, sg)
end
def self.rfc3339(str='-4712-01-01T00:00:00+00:00', sg=ITALY) # :nodoc:
elem = _rfc3339(str)
new_by_frags(elem, sg)
end
def self.xmlschema(str='-4712-01-01', sg=ITALY) # :nodoc:
elem = _xmlschema(str)
new_by_frags(elem, sg)
end
def self.rfc2822(str='Mon, 1 Jan -4712 00:00:00 +0000', sg=ITALY) # :nodoc:
elem = _rfc2822(str)
new_by_frags(elem, sg)
end
class << self; alias_method :rfc822, :rfc2822 end
def self.httpdate(str='Mon, 01 Jan -4712 00:00:00 GMT', sg=ITALY) # :nodoc:
elem = _httpdate(str)
new_by_frags(elem, sg)
end
def self.jisx0301(str='-4712-01-01', sg=ITALY) # :nodoc:
elem = _jisx0301(str)
new_by_frags(elem, sg)
end
class << self
def once(*ids) # :nodoc:
for id in ids
module_eval <<-"end;"
alias_method :__#{id.to_i}__, :#{id.to_s}
private :__#{id.to_i}__
def #{id.to_s}(*args, &block)
(@__#{id.to_i}__ ||= [__#{id.to_i}__(*args, &block)])[0]
end
end;
end
end
private :once
end
# *NOTE* this is the documentation for the method new!(). If
# you are reading this as the documentation for new(), that is
# because rdoc doesn't fully support the aliasing of the
# initialize() method.
# new() is in
# fact an alias for #civil(): read the documentation for that
# method instead.
#
# Create a new Date object.
#
# +ajd+ is the Astronomical Julian Day Number.
# +of+ is the offset from UTC as a fraction of a day.
# Both default to 0.
#
# +sg+ specifies the Day of Calendar Reform to use for this
# Date object.
#
# Using one of the factory methods such as Date::civil is
# generally easier and safer.
def initialize(ajd=0, of=0, sg=ITALY) @ajd, @of, @sg = ajd, of, sg end
# Get the date as an Astronomical Julian Day Number.
def ajd() @ajd end
# Get the date as an Astronomical Modified Julian Day Number.
def amjd() ajd_to_amjd(@ajd) end
once :amjd
# Get the date as a Julian Day Number.
def jd() ajd_to_jd(@ajd, @of)[0] end
# Get any fractional day part of the date.
def day_fraction() ajd_to_jd(@ajd, @of)[1] end
# Get the date as a Modified Julian Day Number.
def mjd() jd_to_mjd(jd) end
# Get the date as the number of days since the Day of Calendar
# Reform (in Italy and the Catholic countries).
def ld() jd_to_ld(jd) end
once :jd, :day_fraction, :mjd, :ld
# Get the date as a Civil Date, [year, month, day_of_month]
def civil() jd_to_civil(jd, @sg) end # :nodoc:
# Get the date as an Ordinal Date, [year, day_of_year]
def ordinal() jd_to_ordinal(jd, @sg) end # :nodoc:
# Get the date as a Commercial Date, [year, week_of_year, day_of_week]
def commercial() jd_to_commercial(jd, @sg) end # :nodoc:
def weeknum0() jd_to_weeknum(jd, 0, @sg) end # :nodoc:
def weeknum1() jd_to_weeknum(jd, 1, @sg) end # :nodoc:
once :civil, :ordinal, :commercial, :weeknum0, :weeknum1
private :civil, :ordinal, :commercial, :weeknum0, :weeknum1
# Get the year of this date.
def year() civil[0] end
# Get the day-of-the-year of this date.
#
# January 1 is day-of-the-year 1
def yday() ordinal[1] end
# Get the month of this date.
#
# January is month 1.
def mon() civil[1] end
# Get the day-of-the-month of this date.
def mday() civil[2] end
alias_method :month, :mon
alias_method :day, :mday
def wnum0() weeknum0[1] end # :nodoc:
def wnum1() weeknum1[1] end # :nodoc:
private :wnum0, :wnum1
# Get the time of this date as [hours, minutes, seconds,
# fraction_of_a_second]
def time() day_fraction_to_time(day_fraction) end # :nodoc:
once :time
private :time
# Get the hour of this date.
def hour() time[0] end
# Get the minute of this date.
def min() time[1] end
# Get the second of this date.
def sec() time[2] end
# Get the fraction-of-a-second of this date.
def sec_fraction() time[3] end
alias_method :minute, :min
alias_method :second, :sec
alias_method :second_fraction, :sec_fraction
private :hour, :min, :sec, :sec_fraction,
:minute, :second, :second_fraction
def zone() strftime('%:z') end
private :zone
# Get the commercial year of this date. See *Commercial* *Date*
# in the introduction for how this differs from the normal year.
def cwyear() commercial[0] end
# Get the commercial week of the year of this date.
def cweek() commercial[1] end
# Get the commercial day of the week of this date. Monday is
# commercial day-of-week 1; Sunday is commercial day-of-week 7.
def cwday() commercial[2] end
# Get the week day of this date. Sunday is day-of-week 0;
# Saturday is day-of-week 6.
def wday() jd_to_wday(jd) end
once :wday
=begin
MONTHNAMES.each_with_index do |n, i|
if n
define_method(n.downcase + '?'){mon == i}
end
end
=end
DAYNAMES.each_with_index do |n, i|
define_method(n.downcase + '?'){wday == i}
end
def nth_kday? (n, k)
k == wday && jd === nth_kday_to_jd(year, mon, n, k, start)
end
private :nth_kday?
# Is the current date old-style (Julian Calendar)?
def julian? () jd < @sg end
# Is the current date new-style (Gregorian Calendar)?
def gregorian? () !julian? end
once :julian?, :gregorian?
def fix_style # :nodoc:
if julian?
then self.class::JULIAN
else self.class::GREGORIAN end
end
private :fix_style
# Is this a leap year?
def leap?
jd_to_civil(civil_to_jd(year, 3, 1, fix_style) - 1,
fix_style)[-1] == 29
end
once :leap?
# When is the Day of Calendar Reform for this Date object?
def start() @sg end
# Create a copy of this Date object using a new Day of Calendar Reform.
def new_start(sg=self.class::ITALY) self.class.new!(@ajd, @of, sg) end
# Create a copy of this Date object that uses the Italian/Catholic
# Day of Calendar Reform.
def italy() new_start(self.class::ITALY) end
# Create a copy of this Date object that uses the English/Colonial
# Day of Calendar Reform.
def england() new_start(self.class::ENGLAND) end
# Create a copy of this Date object that always uses the Julian
# Calendar.
def julian() new_start(self.class::JULIAN) end
# Create a copy of this Date object that always uses the Gregorian
# Calendar.
def gregorian() new_start(self.class::GREGORIAN) end
def offset() @of end
def new_offset(of=0)
if String === of
of = Rational(zone_to_diff(of) || 0, 86400)
end
self.class.new!(@ajd, of, @sg)
end
private :offset, :new_offset
# Return a new Date object that is +n+ days later than the
# current one.
#
# +n+ may be a negative value, in which case the new Date
# is earlier than the current one; however, #-() might be
# more intuitive.
#
# If +n+ is not a Numeric, a TypeError will be thrown. In
# particular, two Dates cannot be added to each other.
def + (n)
case n
when Numeric; return self.class.new!(@ajd + n, @of, @sg)
end
raise TypeError, 'expected numeric'
end
# If +x+ is a Numeric value, create a new Date object that is
# +x+ days earlier than the current one.
#
# If +x+ is a Date, return the number of days between the
# two dates; or, more precisely, how many days later the current
# date is than +x+.
#
# If +x+ is neither Numeric nor a Date, a TypeError is raised.
def - (x)
case x
when Numeric; return self.class.new!(@ajd - x, @of, @sg)
when Date; return @ajd - x.ajd
end
raise TypeError, 'expected numeric or date'
end
# Compare this date with another date.
#
# +other+ can also be a Numeric value, in which case it is
# interpreted as an Astronomical Julian Day Number.
#
# Comparison is by Astronomical Julian Day Number, including
# fractional days. This means that both the time and the
# timezone offset are taken into account when comparing
# two DateTime instances. When comparing a DateTime instance
# with a Date instance, the time of the latter will be
# considered as falling on midnight UTC.
def <=> (other)
case other
when Numeric; return @ajd <=> other
when Date; return @ajd <=> other.ajd
end
nil
end
# The relationship operator for Date.
#
# Compares dates by Julian Day Number. When comparing
# two DateTime instances, or a DateTime with a Date,
# the instances will be regarded as equivalent if they
# fall on the same date in local time.
def === (other)
case other
when Numeric; return jd == other
when Date; return jd == other.jd
end
false
end
def next_day(n=1) self + n end
def prev_day(n=1) self - n end
# Return a new Date one day after this one.
def next() next_day end
alias_method :succ, :next
# Return a new Date object that is +n+ months later than
# the current one.
#
# If the day-of-the-month of the current Date is greater
# than the last day of the target month, the day-of-the-month
# of the returned Date will be the last day of the target month.
def >> (n)
y, m = (year * 12 + (mon - 1) + n).divmod(12)
m, = (m + 1) .divmod(1)
d = mday
d -= 1 until jd2 = _valid_civil?(y, m, d, @sg)
self + (jd2 - jd)
end
# Return a new Date object that is +n+ months earlier than
# the current one.
#
# If the day-of-the-month of the current Date is greater
# than the last day of the target month, the day-of-the-month
# of the returned Date will be the last day of the target month.
def << (n) self >> -n end
def next_month(n=1) self >> n end
def prev_month(n=1) self << n end
def next_year(n=1) self >> n * 12 end
def prev_year(n=1) self << n * 12 end
require 'enumerator'
# Step the current date forward +step+ days at a
# time (or backward, if +step+ is negative) until
# we reach +limit+ (inclusive), yielding the resultant
# date at each step.
def step(limit, step=1) # :yield: date
=begin
if step.zero?
raise ArgumentError, "step can't be 0"
end
=end
unless block_given?
return to_enum(:step, limit, step)
end
da = self
op = %w(- <= >=)[step <=> 0]
while da.__send__(op, limit)
yield da
da += step
end
self
end
# Step forward one day at a time until we reach +max+
# (inclusive), yielding each date as we go.
def upto(max, &block) # :yield: date
step(max, +1, &block)
end
# Step backward one day at a time until we reach +min+
# (inclusive), yielding each date as we go.
def downto(min, &block) # :yield: date
step(min, -1, &block)
end
# Is this Date equal to +other+?
#
# +other+ must both be a Date object, and represent the same date.
def eql? (other) Date === other && self == other end
# Calculate a hash value for this date.
def hash() @ajd.hash end
# Return internal object state as a programmer-readable string.
def inspect() format('#<%s: %s,%s,%s>', self.class, @ajd, @of, @sg) end
# Return the date as a human-readable string.
#
# The format used is YYYY-MM-DD.
def to_s() format('%.4d-%02d-%02d', year, mon, mday) end # 4p
# Dump to Marshal format.
def marshal_dump() [@ajd, @of, @sg] end
# Load from Marshall format.
def marshal_load(a) @ajd, @of, @sg, = a end
end
# Class representing a date and time.
#
# See the documentation to the file date.rb for an overview.
#
# DateTime objects are immutable once created.
#
# == Other methods.
#
# The following methods are defined in Date, but declared private
# there. They are made public in DateTime. They are documented
# here.
#
# === hour()
#
# Get the hour-of-the-day of the time. This is given
# using the 24-hour clock, counting from midnight. The first
# hour after midnight is hour 0; the last hour of the day is
# hour 23.
#
# === min()
#
# Get the minute-of-the-hour of the time.
#
# === sec()
#
# Get the second-of-the-minute of the time.
#
# === sec_fraction()
#
# Get the fraction of a second of the time. This is returned as
# a +Rational+.
#
# === zone()
#
# Get the time zone as a String. This is representation of the
# time offset such as "+1000", not the true time-zone name.
#
# === offset()
#
# Get the time zone offset as a fraction of a day. This is returned
# as a +Rational+.
#
# === new_offset(of=0)
#
# Create a new DateTime object, identical to the current one, except
# with a new time zone offset of +of+. +of+ is the new offset from
# UTC as a fraction of a day.
#
class DateTime < Date
# Create a new DateTime object corresponding to the specified
# Julian Day Number +jd+ and hour +h+, minute +min+, second +s+.
#
# The 24-hour clock is used. Negative values of +h+, +min+, and
# +sec+ are treating as counting backwards from the end of the
# next larger unit (e.g. a +min+ of -2 is treated as 58). No
# wraparound is performed. If an invalid time portion is specified,
# an ArgumentError is raised.
#
# +of+ is the offset from UTC as a fraction of a day (defaults to 0).
# +sg+ specifies the Day of Calendar Reform.
#
# All day/time values default to 0.
def self.jd(jd=0, h=0, min=0, s=0, of=0, sg=ITALY)
unless (jd = _valid_jd?(jd, sg)) &&
(fr = _valid_time?(h, min, s))
raise ArgumentError, 'invalid date'
end
if String === of
of = Rational(zone_to_diff(of) || 0, 86400)
end
new!(jd_to_ajd(jd, fr, of), of, sg)
end
# Create a new DateTime object corresponding to the specified
# Ordinal Date and hour +h+, minute +min+, second +s+.
#
# The 24-hour clock is used. Negative values of +h+, +min+, and
# +sec+ are treating as counting backwards from the end of the
# next larger unit (e.g. a +min+ of -2 is treated as 58). No
# wraparound is performed. If an invalid time portion is specified,
# an ArgumentError is raised.
#
# +of+ is the offset from UTC as a fraction of a day (defaults to 0).
# +sg+ specifies the Day of Calendar Reform.
#
# +y+ defaults to -4712, and +d+ to 1; this is Julian Day Number
# day 0. The time values default to 0.
def self.ordinal(y=-4712, d=1, h=0, min=0, s=0, of=0, sg=ITALY)
unless (jd = _valid_ordinal?(y, d, sg)) &&
(fr = _valid_time?(h, min, s))
raise ArgumentError, 'invalid date'
end
if String === of
of = Rational(zone_to_diff(of) || 0, 86400)
end
new!(jd_to_ajd(jd, fr, of), of, sg)
end
# Create a new DateTime object corresponding to the specified
# Civil Date and hour +h+, minute +min+, second +s+.
#
# The 24-hour clock is used. Negative values of +h+, +min+, and
# +sec+ are treating as counting backwards from the end of the
# next larger unit (e.g. a +min+ of -2 is treated as 58). No
# wraparound is performed. If an invalid time portion is specified,
# an ArgumentError is raised.
#
# +of+ is the offset from UTC as a fraction of a day (defaults to 0).
# +sg+ specifies the Day of Calendar Reform.
#
# +y+ defaults to -4712, +m+ to 1, and +d+ to 1; this is Julian Day
# Number day 0. The time values default to 0.
def self.civil(y=-4712, m=1, d=1, h=0, min=0, s=0, of=0, sg=ITALY)
unless (jd = _valid_civil?(y, m, d, sg)) &&
(fr = _valid_time?(h, min, s))
raise ArgumentError, 'invalid date'
end
if String === of
of = Rational(zone_to_diff(of) || 0, 86400)
end
new!(jd_to_ajd(jd, fr, of), of, sg)
end
class << self; alias_method :new, :civil end
# Create a new DateTime object corresponding to the specified
# Commercial Date and hour +h+, minute +min+, second +s+.
#
# The 24-hour clock is used. Negative values of +h+, +min+, and
# +sec+ are treating as counting backwards from the end of the
# next larger unit (e.g. a +min+ of -2 is treated as 58). No
# wraparound is performed. If an invalid time portion is specified,
# an ArgumentError is raised.
#
# +of+ is the offset from UTC as a fraction of a day (defaults to 0).
# +sg+ specifies the Day of Calendar Reform.
#
# +y+ defaults to -4712, +w+ to 1, and +d+ to 1; this is
# Julian Day Number day 0.
# The time values default to 0.
def self.commercial(y=-4712, w=1, d=1, h=0, min=0, s=0, of=0, sg=ITALY)
unless (jd = _valid_commercial?(y, w, d, sg)) &&
(fr = _valid_time?(h, min, s))
raise ArgumentError, 'invalid date'
end
if String === of
of = Rational(zone_to_diff(of) || 0, 86400)
end
new!(jd_to_ajd(jd, fr, of), of, sg)
end
def self.weeknum(y=-4712, w=0, d=1, f=0, h=0, min=0, s=0, of=0, sg=ITALY) # :nodoc:
unless (jd = _valid_weeknum?(y, w, d, f, sg)) &&
(fr = _valid_time?(h, min, s))
raise ArgumentError, 'invalid date'
end
if String === of
of = Rational(zone_to_diff(of) || 0, 86400)
end
new!(jd_to_ajd(jd, fr, of), of, sg)
end
private_class_method :weeknum
def self.nth_kday(y=-4712, m=1, n=1, k=1, h=0, min=0, s=0, of=0, sg=ITALY) # :nodoc:
unless (jd = _valid_nth_kday?(y, m, n, k, sg)) &&
(fr = _valid_time?(h, min, s))
raise ArgumentError, 'invalid date'
end
if String === of
of = Rational(zone_to_diff(of) || 0, 86400)
end
new!(jd_to_ajd(jd, fr, of), of, sg)
end
private_class_method :nth_kday
def self.new_by_frags(elem, sg) # :nodoc:
elem = rewrite_frags(elem)
elem = complete_frags(elem)
unless (jd = valid_date_frags?(elem, sg)) &&
(fr = valid_time_frags?(elem))
raise ArgumentError, 'invalid date'
end
fr += (elem[:sec_fraction] || 0) / 86400
of = Rational(elem[:offset] || 0, 86400)
new!(jd_to_ajd(jd, fr, of), of, sg)
end
private_class_method :new_by_frags
# Create a new DateTime object by parsing from a String
# according to a specified format.
#
# +str+ is a String holding a date-time representation.
# +fmt+ is the format that the date-time is in. See
# date/format.rb for details on supported formats.
#
# The default +str+ is '-4712-01-01T00:00:00+00:00', and the default
# +fmt+ is '%FT%T%z'. This gives midnight on Julian Day Number day 0.
#
# +sg+ specifies the Day of Calendar Reform.
#
# An ArgumentError will be raised if +str+ cannot be
# parsed.
def self.strptime(str='-4712-01-01T00:00:00+00:00', fmt='%FT%T%z', sg=ITALY)
elem = _strptime(str, fmt)
new_by_frags(elem, sg)
end
# Create a new DateTime object by parsing from a String,
# without specifying the format.
#
# +str+ is a String holding a date-time representation.
# +comp+ specifies whether to interpret 2-digit years
# as 19XX (>= 69) or 20XX (< 69); the default is not to.
# The method will attempt to parse a date-time from the String
# using various heuristics; see #_parse in date/format.rb
# for more details. If parsing fails, an ArgumentError
# will be raised.
#
# The default +str+ is '-4712-01-01T00:00:00+00:00'; this is Julian
# Day Number day 0.
#
# +sg+ specifies the Day of Calendar Reform.
def self.parse(str='-4712-01-01T00:00:00+00:00', comp=true, sg=ITALY)
elem = _parse(str, comp)
new_by_frags(elem, sg)
end
def self.iso8601(str='-4712-01-01T00:00:00+00:00', sg=ITALY) # :nodoc:
elem = _iso8601(str)
new_by_frags(elem, sg)
end
def self.rfc3339(str='-4712-01-01T00:00:00+00:00', sg=ITALY) # :nodoc:
elem = _rfc3339(str)
new_by_frags(elem, sg)
end
def self.xmlschema(str='-4712-01-01T00:00:00+00:00', sg=ITALY) # :nodoc:
elem = _xmlschema(str)
new_by_frags(elem, sg)
end
def self.rfc2822(str='Mon, 1 Jan -4712 00:00:00 +0000', sg=ITALY) # :nodoc:
elem = _rfc2822(str)
new_by_frags(elem, sg)
end
class << self; alias_method :rfc822, :rfc2822 end
def self.httpdate(str='Mon, 01 Jan -4712 00:00:00 GMT', sg=ITALY) # :nodoc:
elem = _httpdate(str)
new_by_frags(elem, sg)
end
def self.jisx0301(str='-4712-01-01T00:00:00+00:00', sg=ITALY) # :nodoc:
elem = _jisx0301(str)
new_by_frags(elem, sg)
end
public :hour, :min, :sec, :sec_fraction, :zone, :offset, :new_offset,
:minute, :second, :second_fraction
def to_s # 4p
format('%.4d-%02d-%02dT%02d:%02d:%02d%s',
year, mon, mday, hour, min, sec, zone)
end
end
class Time
def to_time() getlocal end
def to_date
jd = Date.__send__(:civil_to_jd, year, mon, mday, Date::ITALY)
Date.new!(Date.__send__(:jd_to_ajd, jd, 0, 0), 0, Date::ITALY)
end
def to_datetime
jd = DateTime.__send__(:civil_to_jd, year, mon, mday, DateTime::ITALY)
fr = DateTime.__send__(:time_to_day_fraction, hour, min, [sec, 59].min) +
Rational(nsec, 86400_000_000_000)
of = Rational(utc_offset, 86400)
DateTime.new!(DateTime.__send__(:jd_to_ajd, jd, fr, of),
of, DateTime::ITALY)
end
end
class Date
def to_time() Time.local(year, mon, mday) end
def to_date() self end
def to_datetime() DateTime.new!(jd_to_ajd(jd, 0, 0), @of, @sg) end
# Create a new Date object representing today.
#
# +sg+ specifies the Day of Calendar Reform.
def self.today(sg=ITALY) Time.now.to_date .new_start(sg) end
# Create a new DateTime object representing the current time.
#
# +sg+ specifies the Day of Calendar Reform.
def self.now (sg=ITALY) Time.now.to_datetime.new_start(sg) end
private_class_method :now
end
class DateTime < Date
def to_time
d = new_offset(0)
d.instance_eval do
Time.utc(year, mon, mday, hour, min, sec +
sec_fraction)
end.
getlocal
end
def to_date() Date.new!(jd_to_ajd(jd, 0, 0), 0, @sg) end
def to_datetime() self end
private_class_method :today
public_class_method :now
end
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