# # date.rb - date and time library # # Author: Tadayoshi Funaba 1998-2007 # # Documentation: William Webber # #-- # $Id: date.rb,v 2.32 2007-12-01 18:51:16+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}.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; d <=> other.d when Numeric; 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 UNIXEPOCH = 2440588 # 1970-01-01 :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 + 1.to_r/2).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 - 1.to_r/2 end # :nodoc: # Convert a fractional day +fr+ to [hours, minutes, seconds, # fraction_of_a_second] def day_fraction_to_time(fr) # :nodoc: h, fr = fr.divmod(1.to_r/24) min, fr = fr.divmod(1.to_r/1440) s, fr = fr.divmod(1.to_r/86400) return h, min, s, fr * 86400 end # Convert an +h+ hour, +min+ minutes, +s+ seconds period # to a fractional day. def time_to_day_fraction(h, min, s) # :nodoc: h.to_r/24 + min.to_r/1440 + s.to_r/86400 end # Convert an Astronomical Modified Julian Day Number to an # Astronomical Julian Day Number. def amjd_to_ajd(amjd) amjd + 4800001.to_r/2 end # :nodoc: # Convert an Astronomical Julian Day Number to an # Astronomical Modified Julian Day Number. def ajd_to_amjd(ajd) ajd - 4800001.to_r/2 end # :nodoc: # Convert a Modified Julian Day Number to a Julian # Day Number. def mjd_to_jd(mjd) mjd + 2400001 end # :nodoc: # Convert a Julian Day Number to a Modified Julian Day # Number. def jd_to_mjd(jd) jd - 2400001 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 + 2299160 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 - 2299160 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..23) === h && (0..59) === min && (0..59) === 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] = UNIXEPOCH + 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', hints={}, sg=ITALY) elem = _parse(str, hints) 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 private :hour, :min, :sec, :sec_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 = (zone_to_diff(of) || 0).to_r/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() strftime end # 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 = (zone_to_diff(of) || 0).to_r/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 = (zone_to_diff(of) || 0).to_r/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 = (zone_to_diff(of) || 0).to_r/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 = (zone_to_diff(of) || 0).to_r/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 = (zone_to_diff(of) || 0).to_r/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 = (zone_to_diff(of) || 0).to_r/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 sf = (elem[:sec_fraction] || 0) fr += sf/86400 of = (elem[:offset] || 0) of = of.to_r/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', hints={}, sg=ITALY) elem = _parse(str, hints) 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 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) + nsec.to_r/86400_000_000_000 of = utc_offset.to_r/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