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authortadf <tadf@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2011-03-11 15:07:47 +0000
committertadf <tadf@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2011-03-11 15:07:47 +0000
commitf809440332cb82b7c933433a59a0eb1fbc092eb3 (patch)
tree88b68a34e0cfde034e62ccca4e572537d8663d5d /ext/date/lib/date.rb
parent725e9ee966ad1d697a421c9300c44150e268e849 (diff)
* ext/date/lib: moved from lib.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@31095 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
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+#
+# date.rb - date and time library
+#
+# Author: Tadayoshi Funaba 1998-2011
+#
+# Documentation: William Webber <william@williamwebber.com>
+#
+# == 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 Ethiopic Solar Calendar,
+# the Islamic Lunar 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 Era.
+#
+# === 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.
+#
+# === Offsets
+#
+# DateTime objects support a simple representation
+# of offsets. Offsets are represented as an offset
+# from UTC (UTC is not identical GMT; GMT is a historical term),
+# as a fraction of a day. This offset is the
+# how much local time is later (or earlier) than UTC.
+# 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 offsets 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 offsets, in that
+# there is no way to create a Date object with non-utc offset.
+#
+# == Examples of use
+#
+# === Print out the date of every Sunday between two dates.
+#
+# def print_sundays(d1, d2)
+# d1 += 1 until d1.sunday?
+# d1.step(d2, 7) do |d|
+# puts d.strftime('%B %-d')
+# end
+# end
+#
+# print_sundays(Date.new(2003, 4, 8), Date.new(2003, 5, 23))
+
+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
+
+ # now only for marshal dumped
+ 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
+
+ def to_f
+ return 0 if @d == 0
+ if @d > 0
+ Float::INFINITY
+ else
+ -Float::INFINITY
+ 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 = Float::INFINITY
+
+ # A constant used to indicate that a Date should always use the
+ # Gregorian calendar.
+ GREGORIAN = -Float::INFINITY
+
+ 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]
+ j = commercial_to_jd(a + 1, 1, 1, sg)
+ if jd >= j
+ y = a + 1
+ else
+ j = commercial_to_jd(a, 1, 1, sg)
+ y = a
+ end
+ w = 1 + ((jd - j) / 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, _, 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, = 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
+
+ def day_fraction_to_time_wo_sf(fr) # :nodoc:
+ ss = fr.div(SECONDS_IN_DAY) # 4p
+ h, ss = ss.divmod(3600)
+ min, s = ss.divmod(60)
+ return h, min, s
+ 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
+ return unless 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
+ return unless 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, =
+ 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, =
+ 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, =
+ 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
+
+ def self.valid_jd_r? (jd, sg=ITALY)
+ !!_valid_jd?(jd, sg)
+ end
+
+ private_class_method :valid_jd_r?
+
+ def self.valid_ordinal_r? (y, d, sg=ITALY)
+ !!_valid_ordinal?(y, d, sg)
+ end
+
+ private_class_method :valid_ordinal_r?
+
+ def self.valid_civil_r? (y, m, d, sg=ITALY)
+ !!_valid_civil?(y, m, d, sg)
+ end
+
+ private_class_method :valid_civil_r?
+
+ def self.valid_commercial_r? (y, w, d, sg=ITALY)
+ !!_valid_commercial?(y, w, d, sg)
+ end
+
+ private_class_method :valid_commercial_r?
+
+ 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?
+
+ def self.new!(ajd=0, of=0, sg=ITALY)
+ jd, df = ajd_to_jd(ajd, 0)
+ if !(Fixnum === jd) ||
+ jd < sg || df !=0 || of != 0 ||
+ jd < -327 || jd > 366963925
+ return new_r!(ajd, of, sg)
+ end
+ new_l!(jd, sg)
+ end
+
+ # 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_r(jd=0, sg=ITALY) # :nodoc:
+ jd = _valid_jd?(jd, sg)
+ new_r!(jd_to_ajd(jd, 0, 0), 0, sg)
+ end
+
+ private_class_method :jd_r
+
+ # 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_r(y=-4712, d=1, sg=ITALY) # :nodoc:
+ unless jd = _valid_ordinal?(y, d, sg)
+ raise ArgumentError, 'invalid date'
+ end
+ new_r!(jd_to_ajd(jd, 0, 0), 0, sg)
+ end
+
+ private_class_method :ordinal_r
+
+ # 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_r(y=-4712, m=1, d=1, sg=ITALY) # :nodoc:
+ unless jd = _valid_civil?(y, m, d, sg)
+ raise ArgumentError, 'invalid date'
+ end
+ new_r!(jd_to_ajd(jd, 0, 0), 0, sg)
+ end
+
+ private_class_method :civil_r
+
+ # 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_r(y=-4712, w=1, d=1, sg=ITALY) # :nodoc:
+ unless jd = _valid_commercial?(y, w, d, sg)
+ raise ArgumentError, 'invalid date'
+ end
+ new_r!(jd_to_ajd(jd, 0, 0), 0, sg)
+ end
+
+ private_class_method :commercial_r
+
+ 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] ||= 1
+ 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 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: -- restricted
+ for id in ids
+ module_eval <<-"end;"
+ alias_method :__#{id.object_id}__, :#{id.to_s}
+ private :__#{id.object_id}__
+ def #{id.to_s}(*args)
+ __ca__[#{id.object_id}] ||= __#{id.object_id}__(*args)
+ end
+ end;
+ end
+ end # <<dummy
+
+ private :once
+
+ end
+
+ # Get the date as an Astronomical Modified Julian Day Number.
+ def amjd_r() ajd_to_amjd(ajd) end
+
+ once :amjd_r
+
+ def daynum() ajd_to_jd(ajd, offset) end
+
+ once :daynum
+ private :daynum
+
+ # Get the date as a Julian Day Number.
+ def jd_r() daynum[0] end # :nodoc:
+
+ # Get any fractional day part of the date.
+ def day_fraction_r() daynum[1] end # :nodoc:
+
+ # Get the date as a Modified Julian Day Number.
+ def mjd_r() jd_to_mjd(jd) end # :nodoc:
+
+ # Get the date as the number of days since the Day of Calendar
+ # Reform (in Italy and the Catholic countries).
+ def ld_r() jd_to_ld(jd) end # :nodoc:
+
+ once :jd_r, :day_fraction_r, :mjd_r, :ld_r
+ private :jd_r, :day_fraction_r, :mjd_r, :ld_r
+
+ # Get the date as a Civil Date, [year, month, day_of_month]
+ def civil() jd_to_civil(jd, start) end # :nodoc:
+
+ # Get the date as an Ordinal Date, [year, day_of_year]
+ def ordinal() jd_to_ordinal(jd, start) end # :nodoc:
+
+ # Get the date as a Commercial Date, [year, week_of_year, day_of_week]
+ def commercial() jd_to_commercial(jd, start) end # :nodoc:
+
+ def weeknum0() jd_to_weeknum(jd, 0, start) end # :nodoc:
+ def weeknum1() jd_to_weeknum(jd, 1, start) end # :nodoc:
+
+ once :civil, :ordinal, :commercial, :weeknum0, :weeknum1
+ private :civil, :ordinal, :commercial, :weeknum0, :weeknum1
+
+ # Get the year of this date.
+ def year_r() civil[0] end # :nodoc:
+
+ # Get the day-of-the-year of this date.
+ #
+ # January 1 is day-of-the-year 1
+ def yday_r() ordinal[1] end # :nodoc:
+
+ # Get the month of this date.
+ #
+ # January is month 1.
+ def mon_r() civil[1] end # :nodoc:
+
+ # Get the day-of-the-month of this date.
+ def mday_r() civil[2] end # :nodoc:
+
+ private :year_r, :yday_r, :mon_r, :mday_r
+
+ def wnum0_r() weeknum0[1] end # :nodoc:
+ def wnum1_r() weeknum1[1] end # :nodoc:
+
+ private :wnum0_r, :wnum1_r
+
+ # Get the time of this date as [hours, minutes, seconds,
+ # fraction_of_a_second]
+ def time() day_fraction_to_time(day_fraction) end # :nodoc:
+ def time_wo_sf() day_fraction_to_time_wo_sf(day_fraction) end # :nodoc:
+ def time_sf() day_fraction % SECONDS_IN_DAY * 86400 end # :nodoc:
+
+ once :time, :time_wo_sf, :time_sf
+ private :time, :time_wo_sf, :time_sf
+
+ # Get the hour of this date.
+ def hour_r() time_wo_sf[0] end # :nodoc: # 4p
+
+ # Get the minute of this date.
+ def min_r() time_wo_sf[1] end # :nodoc: # 4p
+
+ # Get the second of this date.
+ def sec_r() time_wo_sf[2] end # :nodoc: # 4p
+
+ # Get the fraction-of-a-second of this date.
+ def sec_fraction_r() time_sf end # 4p
+
+ private :hour_r, :min_r, :sec_r, :sec_fraction_r
+
+ def zone_r # :nodoc: # 4p - strftime('%:z')
+ sign = if offset < 0 then '-' else '+' end
+ fr = offset.abs
+ ss = fr.div(SECONDS_IN_DAY)
+ hh, ss = ss.divmod(3600)
+ mm = ss.div(60)
+ format('%s%02d:%02d', sign, hh, mm)
+ end
+
+ private :zone_r
+
+ # Get the commercial year of this date. See *Commercial* *Date*
+ # in the introduction for how this differs from the normal year.
+ def cwyear_r() commercial[0] end # :nodoc:
+
+ # Get the commercial week of the year of this date.
+ def cweek_r() commercial[1] end # :nodoc:
+
+ # 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_r() commercial[2] end # :nodoc:
+
+ private :cwyear_r, :cweek_r, :cwday_r
+
+ # Get the week day of this date. Sunday is day-of-week 0;
+ # Saturday is day-of-week 6.
+ def wday_r() jd_to_wday(jd) end # :nodoc:
+
+ once :wday_r
+ private :wday_r
+
+=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) # :nodoc:
+ 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_r? () jd < start end # :nodoc:
+
+ # Is the current date new-style (Gregorian Calendar)?
+ def gregorian_r? () !julian? end # :nodoc:
+
+ once :julian_r?, :gregorian_r?
+ private :julian_r?, :gregorian_r?
+
+ 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_r? # :nodoc:
+ jd_to_civil(civil_to_jd(year, 3, 1, fix_style) - 1,
+ fix_style)[-1] == 29
+ end
+
+ once :leap_r?
+ private :leap_r?
+
+ # When is the Day of Calendar Reform for this Date object?
+ def start_r() @sg end # :nodoc:
+
+ # Create a copy of this Date object using a new Day of Calendar Reform.
+ def new_start_r(sg=self.class::ITALY) self.class.new_r!(ajd, offset, sg) end # :nodoc:
+
+ private :start_r, :new_start_r
+
+ # 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 new_offset_r(of=0) # :nodoc:
+ if String === of
+ of = Rational(zone_to_diff(of) || 0, 86400)
+ elsif Float === of
+ of = Rational((of * 86400).round, 86400)
+ end
+ self.class.new_r!(ajd, of, start)
+ end
+
+ private :new_offset_r
+
+ # 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 plus_r (n) # :nodoc:
+ case n
+ when Numeric
+ if Float === n
+ n = Rational((n * 86400000000000).round, 86400000000000)
+ end
+ return self.class.new_r!(ajd + n, offset, start)
+ end
+ raise TypeError, 'expected numeric'
+ end
+
+ private :plus_r
+
+ # 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 minus_r (x) # :nodoc:
+ case x
+ when Numeric
+ if Float === x
+ x = Rational((x * 86400000000000).round, 86400000000000)
+ end
+ return self.class.new_r!(ajd - x, offset, start)
+ when Date
+ return ajd - x.ajd
+ end
+ raise TypeError, 'expected numeric or date'
+ end
+
+ private :minus_r
+
+ # 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
+ # 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 cmp_r (other) # :nodoc:
+ case other
+ when Numeric; return ajd <=> other
+ when Date; return ajd <=> other.ajd
+ else
+ begin
+ l, r = other.coerce(self)
+ return l <=> r
+ rescue NoMethodError
+ end
+ end
+ nil
+ end
+
+ private :cmp_r
+
+ # 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 equal_r (other) # :nodoc:
+ case other
+ when Numeric; return jd == other
+ when Date; return jd == other.jd
+ else
+ begin
+ l, r = other.coerce(self)
+ return l === r
+ rescue NoMethodError
+ end
+ end
+ false
+ end
+
+ private :equal_r
+
+ 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
+ until jd2 = _valid_civil?(y, m, d, start)
+ d -= 1
+ raise ArgumentError, 'invalid date' unless d > 0
+ end
+ 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_r? (other) Date === other && self == other end # :nodoc:
+
+ private :eql_r?
+
+ # Calculate a hash value for this date.
+ def hash_r() ajd.hash end # :nodoc:
+
+ private :hash_r
+
+ # Return internal object state as a programmer-readable string.
+ def inspect_r # :nodoc:
+ format('#<%s[R]: %s (%s,%s,%s)>', self.class, to_s_r, ajd, offset, start)
+ end
+
+ private :inspect_r
+
+ # Return the date as a human-readable string.
+ #
+ # The format used is YYYY-MM-DD.
+ def to_s_r() format('%.4d-%02d-%02d', year, mon, mday) end # :nodoc: # 4p
+
+ private :to_s_r
+
+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 "+10:00".
+#
+# === 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
+
+ def self.new!(ajd=0, of=0, sg=ITALY)
+ jd, df = ajd_to_jd(ajd, 0)
+ df, sf = (df * 86400).divmod(1)
+ sf, ssf = (sf * 1000000000).divmod(1)
+ odf, osf = (of * 86400).divmod(1)
+ if !(Fixnum === jd) ||
+ jd < sg || ssf != 0 || osf != 0 ||
+ jd < -327 || jd > 366963925
+ return new_r!(ajd, of, sg)
+ end
+ new_l!(jd, df, sf, odf, sg)
+ end
+
+ # 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_r(jd=0, h=0, min=0, s=0, of=0, sg=ITALY) # :nodoc:
+ 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)
+ elsif Float === of
+ of = Rational((of * 86400).round, 86400)
+ end
+ new_r!(jd_to_ajd(jd, fr, of), of, sg)
+ end
+
+ private_class_method :jd_r
+
+ # 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_r(y=-4712, d=1, h=0, min=0, s=0, of=0, sg=ITALY) # :nodoc:
+ 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)
+ elsif Float === of
+ of = Rational((of * 86400).round, 86400)
+ end
+ new_r!(jd_to_ajd(jd, fr, of), of, sg)
+ end
+
+ private_class_method :ordinal_r
+
+ # 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_r(y=-4712, m=1, d=1, h=0, min=0, s=0, of=0, sg=ITALY) # :nodoc:
+ 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)
+ elsif Float === of
+ of = Rational((of * 86400).round, 86400)
+ end
+ new_r!(jd_to_ajd(jd, fr, of), of, sg)
+ end
+
+ private_class_method :civil_r
+
+ # 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_r(y=-4712, w=1, d=1, h=0, min=0, s=0, of=0, sg=ITALY) # :nodoc:
+ 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)
+ elsif Float === of
+ of = Rational((of * 86400).round, 86400)
+ end
+ new_r!(jd_to_ajd(jd, fr, of), of, sg)
+ end
+
+ private_class_method :commercial_r
+
+ 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)
+ elsif Float === of
+ of = Rational((of * 86400).round, 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)
+ elsif Float === of
+ of = Rational((of * 86400).round, 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 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.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
+
+ def to_s_r # :nodoc: # 4p
+ format('%.4d-%02d-%02dT%02d:%02d:%02d%s',
+ year, mon, mday, hour, min, sec, zone)
+ end
+
+ private :to_s_r
+
+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(subsec, 86400)
+ 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), offset, start) end
+
+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, start) end
+ def to_datetime() self end
+
+end
+
+require 'date_core'