lib/core_ext/date_and_time/calculations.rb
module DateAndTime
module Calculations
DAYS_INTO_WEEK = {
:monday => 0,
:tuesday => 1,
:wednesday => 2,
:thursday => 3,
:friday => 4,
:saturday => 5,
:sunday => 6
}
WEEKEND_DAYS = [ 6, 0 ]
# Returns a new date/time representing yesterday.
def yesterday
advance(days: -1)
end
# Returns a new date/time representing the previous day.
def prev_day
advance(days: -1)
end
# Returns a new date/time representing tomorrow.
def tomorrow
advance(days: 1)
end
# Returns a new date/time representing the next day.
def next_day
advance(days: 1)
end
# Returns true if the date/time is today.
def today?
to_date == ::Date.current
end
# Returns true if the date/time is in the past.
def past?
self < self.class.current
end
# Returns true if the date/time is in the future.
def future?
self > self.class.current
end
# Returns true if the date/time falls on a Saturday or Sunday.
def on_weekend?
WEEKEND_DAYS.include?(wday)
end
# Returns a new date/time the specified number of days ago.
def days_ago(days)
advance(:days => -days)
end
# Returns a new date/time the specified number of days in the future.
def days_since(days)
advance(:days => days)
end
# Returns a new date/time the specified number of weeks ago.
def weeks_ago(weeks)
advance(:weeks => -weeks)
end
# Returns a new date/time the specified number of weeks in the future.
def weeks_since(weeks)
advance(:weeks => weeks)
end
# Returns a new date/time the specified number of months ago.
def months_ago(months)
advance(:months => -months)
end
# Returns a new date/time the specified number of months in the future.
def months_since(months)
advance(:months => months)
end
# Returns a new date/time the specified number of years ago.
def years_ago(years)
advance(:years => -years)
end
# Returns a new date/time the specified number of years in the future.
def years_since(years)
advance(:years => years)
end
# Returns a new date/time at the start of the month.
#
# today = Date.today # => Thu, 18 Jun 2015
# today.beginning_of_month # => Mon, 01 Jun 2015
#
# +DateTime+ objects will have a time set to 0:00.
#
# now = DateTime.current # => Thu, 18 Jun 2015 15:23:13 +0000
# now.beginning_of_month # => Mon, 01 Jun 2015 00:00:00 +0000
def beginning_of_month
first_hour(change(:day => 1))
end
alias :at_beginning_of_month :beginning_of_month
# Returns a new date/time at the start of the quarter.
#
# today = Date.today # => Fri, 10 Jul 2015
# today.beginning_of_quarter # => Wed, 01 Jul 2015
#
# +DateTime+ objects will have a time set to 0:00.
#
# now = DateTime.current # => Fri, 10 Jul 2015 18:41:29 +0000
# now.beginning_of_quarter # => Wed, 01 Jul 2015 00:00:00 +0000
def beginning_of_quarter
first_quarter_month = [10, 7, 4, 1].detect { |m| m <= month }
beginning_of_month.change(:month => first_quarter_month)
end
alias :at_beginning_of_quarter :beginning_of_quarter
# Returns a new date/time at the end of the quarter.
#
# today = Date.today # => Fri, 10 Jul 2015
# today.end_of_quarter # => Wed, 30 Sep 2015
#
# +DateTime+ objects will have a time set to 23:59:59.
#
# now = DateTime.current # => Fri, 10 Jul 2015 18:41:29 +0000
# now.end_of_quarter # => Wed, 30 Sep 2015 23:59:59 +0000
def end_of_quarter
last_quarter_month = [3, 6, 9, 12].detect { |m| m >= month }
beginning_of_month.change(:month => last_quarter_month).end_of_month
end
alias :at_end_of_quarter :end_of_quarter
# Returns a new date/time at the beginning of the year.
#
# today = Date.today # => Fri, 10 Jul 2015
# today.beginning_of_year # => Thu, 01 Jan 2015
#
# +DateTime+ objects will have a time set to 0:00.
#
# now = DateTime.current # => Fri, 10 Jul 2015 18:41:29 +0000
# now.beginning_of_year # => Thu, 01 Jan 2015 00:00:00 +0000
def beginning_of_year
change(:month => 1).beginning_of_month
end
alias :at_beginning_of_year :beginning_of_year
# Returns a new date/time representing the given day in the next week.
#
# today = Date.today # => Thu, 07 May 2015
# today.next_week # => Mon, 11 May 2015
#
# The +given_day_in_next_week+ defaults to the beginning of the week
# which is determined by +Date.beginning_of_week+ or +config.beginning_of_week+
# when set.
#
# today = Date.today # => Thu, 07 May 2015
# today.next_week(:friday) # => Fri, 15 May 2015
#
# +DateTime+ objects have their time set to 0:00 unless +same_time+ is true.
#
# now = DateTime.current # => Thu, 07 May 2015 13:31:16 +0000
# now.next_week # => Mon, 11 May 2015 00:00:00 +0000
def next_week(given_day_in_next_week = Date.beginning_of_week, same_time: false)
result = first_hour(weeks_since(1).beginning_of_week.days_since(days_span(given_day_in_next_week)))
same_time ? copy_time_to(result) : result
end
# Returns a new date/time representing the next weekday.
def next_weekday
if next_day.on_weekend?
next_week(:monday, same_time: true)
else
next_day
end
end
# Short-hand for months_since(1).
def next_month
months_since(1)
end
# Short-hand for months_since(3)
def next_quarter
months_since(3)
end
# Short-hand for years_since(1).
def next_year
years_since(1)
end
# Returns a new date/time representing the given day in the previous week.
# Week is assumed to start on +start_day+, default is
# +Date.beginning_of_week+ or +config.beginning_of_week+ when set.
# DateTime objects have their time set to 0:00 unless +same_time+ is true.
def prev_week(start_day = Date.beginning_of_week, same_time: false)
result = first_hour(weeks_ago(1).beginning_of_week.days_since(days_span(start_day)))
same_time ? copy_time_to(result) : result
end
alias_method :last_week, :prev_week
# Returns a new date/time representing the previous weekday.
def prev_weekday
if prev_day.on_weekend?
copy_time_to(beginning_of_week(:friday))
else
prev_day
end
end
alias_method :last_weekday, :prev_weekday
# Short-hand for months_ago(1).
def prev_month
months_ago(1)
end
alias_method :last_month, :prev_month
# Short-hand for months_ago(3).
def prev_quarter
months_ago(3)
end
alias_method :last_quarter, :prev_quarter
# Short-hand for years_ago(1).
def prev_year
years_ago(1)
end
alias_method :last_year, :prev_year
# Returns the number of days to the start of the week on the given day.
# Week is assumed to start on +start_day+, default is
# +Date.beginning_of_week+ or +config.beginning_of_week+ when set.
def days_to_week_start(start_day = Date.beginning_of_week)
start_day_number = DAYS_INTO_WEEK[start_day]
current_day_number = wday != 0 ? wday - 1 : 6
(current_day_number - start_day_number) % 7
end
# Returns a new date/time representing the start of this week on the given day.
# Week is assumed to start on +start_day+, default is
# +Date.beginning_of_week+ or +config.beginning_of_week+ when set.
# +DateTime+ objects have their time set to 0:00.
def beginning_of_week(start_day = Date.beginning_of_week)
result = days_ago(days_to_week_start(start_day))
acts_like?(:time) ? result.midnight : result
end
alias :at_beginning_of_week :beginning_of_week
# Returns Monday of this week assuming that week starts on Monday.
# +DateTime+ objects have their time set to 0:00.
def monday
beginning_of_week(:monday)
end
# Returns a new date/time representing the end of this week on the given day.
# Week is assumed to start on +start_day+, default is
# +Date.beginning_of_week+ or +config.beginning_of_week+ when set.
# DateTime objects have their time set to 23:59:59.
def end_of_week(start_day = Date.beginning_of_week)
last_hour(days_since(6 - days_to_week_start(start_day)))
end
alias :at_end_of_week :end_of_week
# Returns Sunday of this week assuming that week starts on Monday.
# +DateTime+ objects have their time set to 23:59:59.
def sunday
end_of_week(:monday)
end
# Returns a new date/time representing the end of the month.
# DateTime objects will have a time set to 23:59:59.
def end_of_month
last_day = ::Time.days_in_month(month, year)
last_hour(days_since(last_day - day))
end
alias :at_end_of_month :end_of_month
# Returns a new date/time representing the end of the year.
# DateTime objects will have a time set to 23:59:59.
def end_of_year
change(:month => 12).end_of_month
end
alias :at_end_of_year :end_of_year
# Returns a Range representing the whole week of the current date/time.
# Week starts on start_day, default is <tt>Date.week_start</tt> or <tt>config.week_start</tt> when set.
def all_week(start_day = Date.beginning_of_week)
beginning_of_week(start_day)..end_of_week(start_day)
end
# Returns a Range representing the whole month of the current date/time.
def all_month
beginning_of_month..end_of_month
end
# Returns a Range representing the whole quarter of the current date/time.
def all_quarter
beginning_of_quarter..end_of_quarter
end
# Returns a Range representing the whole year of the current date/time.
def all_year
beginning_of_year..end_of_year
end
private
def first_hour(date_or_time)
date_or_time.acts_like?(:time) ? date_or_time.beginning_of_day : date_or_time
end
def last_hour(date_or_time)
date_or_time.acts_like?(:time) ? date_or_time.end_of_day : date_or_time
end
def days_span(day)
(DAYS_INTO_WEEK[day] - DAYS_INTO_WEEK[Date.beginning_of_week]) % 7
end
def copy_time_to(other)
other.change(hour: hour, min: min, sec: sec, usec: try(:usec))
end
end
end