require 'rational' class DateTime class << self # DateTimes aren't aware of DST rules, so use a consistent non-DST offset when creating a DateTime with an offset in the local zone def local_offset ::Time.local(2007).utc_offset.to_r / 86400 end def current ::Time.zone_default ? ::Time.zone.now.to_datetime : ::Time.now.to_datetime end end # Tells whether the DateTime object's datetime lies in the past def past? self < ::DateTime.current end # Tells whether the DateTime object's datetime lies in the future def future? self > ::DateTime.current end # Seconds since midnight: DateTime.now.seconds_since_midnight def seconds_since_midnight sec + (min * 60) + (hour * 3600) end # Returns a new DateTime where one or more of the elements have been changed according to the +options+ parameter. The time options # (hour, minute, sec) reset cascadingly, so if only the hour is passed, then minute and sec is set to 0. If the hour and # minute is passed, then sec is set to 0. def change(options) ::DateTime.civil( options[:year] || year, options[:month] || month, options[:day] || day, options[:hour] || hour, options[:min] || (options[:hour] ? 0 : min), options[:sec] || ((options[:hour] || options[:min]) ? 0 : sec), options[:offset] || offset, options[:start] || start ) end # Uses Date to provide precise Time calculations for years, months, and days. # The +options+ parameter takes a hash with any of these keys: :years, # :months, :weeks, :days, :hours, # :minutes, :seconds. def advance(options) d = to_date.advance(options) datetime_advanced_by_date = change(:year => d.year, :month => d.month, :day => d.day) seconds_to_advance = (options[:seconds] || 0) + (options[:minutes] || 0) * 60 + (options[:hours] || 0) * 3600 seconds_to_advance == 0 ? datetime_advanced_by_date : datetime_advanced_by_date.since(seconds_to_advance) end # Returns a new DateTime representing the time a number of seconds ago # Do not use this method in combination with x.months, use months_ago instead! def ago(seconds) since(-seconds) end # Returns a new DateTime representing the time a number of seconds since the instance time # Do not use this method in combination with x.months, use months_since instead! def since(seconds) self + Rational(seconds.round, 86400) end alias :in :since # Returns a new DateTime representing the start of the day (0:00) def beginning_of_day change(:hour => 0) end alias :midnight :beginning_of_day alias :at_midnight :beginning_of_day alias :at_beginning_of_day :beginning_of_day # Returns a new DateTime representing the end of the day (23:59:59) def end_of_day change(:hour => 23, :min => 59, :sec => 59) end # Adjusts DateTime to UTC by adding its offset value; offset is set to 0 # # Example: # # DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-6, 24)) # => Mon, 21 Feb 2005 10:11:12 -0600 # DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-6, 24)).utc # => Mon, 21 Feb 2005 16:11:12 +0000 def utc new_offset(0) end alias_method :getutc, :utc # Returns true if offset == 0 def utc? offset == 0 end # Returns the offset value in seconds def utc_offset (offset * 86400).to_i end # Layers additional behavior on DateTime#<=> so that Time and ActiveSupport::TimeWithZone instances can be compared with a DateTime def compare_with_coercion(other) other = other.comparable_time if other.respond_to?(:comparable_time) other = other.to_datetime unless other.acts_like?(:date) compare_without_coercion(other) end alias_method :compare_without_coercion, :<=> alias_method :<=>, :compare_with_coercion end