time.rb

class Integer
  # Enables the use of time calculations and declarations, like 45.minutes + 2.hours + 4.years.
  #
  # These methods use Time#advance for precise date calculations when using from_now, ago, etc.
  # as well as adding or subtracting their results from a Time object. For example:
  #
  #   # equivalent to Time.now.advance(:months => 1)
  #   1.month.from_now
  #
  #   # equivalent to Time.now.advance(:years => 2)
  #   2.years.from_now
  #
  #   # equivalent to Time.now.advance(:months => 4, :years => 5)
  #   (4.months + 5.years).from_now
  #
  # While these methods provide precise calculation when used as in the examples above, care
  # should be taken to note that this is not true if the result of `months', `years', etc is
  # converted before use:
  #
  #   # equivalent to 30.days.to_i.from_now
  #   1.month.to_i.from_now
  #
  #   # equivalent to 365.25.days.to_f.from_now
  #   1.year.to_f.from_now
  #
  # In such cases, Ruby's core
  # Date[http://stdlib.rubyonrails.org/libdoc/date/rdoc/index.html] and
  # Time[http://stdlib.rubyonrails.org/libdoc/time/rdoc/index.html] should be used for precision
  # date and time arithmetic
  def months
    ActiveSupport::Duration.new(self * 30.days, [[:months, self]])
  end
  alias :month :months

  def years
    ActiveSupport::Duration.new(self * 365.25.days, [[:years, self]])
  end
  alias :year :years
end