require 'rational' unless RUBY_VERSION >= '1.9.2'
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
# Returns <tt>Time.zone.now.to_datetime</tt> when <tt>Time.zone</tt> or <tt>config.time_zone</tt> are set, otherwise returns <tt>Time.now.to_datetime</tt>.
def current
::Time.zone ? ::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: <tt>:years</tt>,
# <tt>:months</tt>, <tt>:weeks</tt>, <tt>:days</tt>, <tt>:hours</tt>,
# <tt>:minutes</tt>, <tt>:seconds</tt>.
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 <=>(other)
super other.to_datetime
end
end