Random time extention

random_time.rb

class Date

  # Samples a random time
  #
  # Parameters
  # This takes up to three parameters, that is a range of `years`, `months` and
  # `days`. Each defining the boundries of the sample date.
  #
  # Examples
  # `Time.random({ years: 1..2 })` will produce a date between one and two
  #   ears into the future.
  #
  # `Time.random({ years: -5..5 })` will produce a date after five years ago,
  #   but before five ears from now.
  #
  # `Time.random({ years: 1..1 })` will produce a date within the next year
  #
  # `Time.random({ years: 1..1, months: 3..5 })` will produce a date within
  #   this year, and between march and may
  #
  # `Time.random({ years: 1..1, months: 3..5, days: 20..25 })` will produce a
  #   date between the 20th and 25th between march and may of this year.
  #
  def self.random(options = {})
    years  = options[:years]  || (-5..5)
    months = options[:months] || (1..12)

    year = years.to_a.collect{ |y| y >= 0 ? y.years.from_now.year : y.abs.years.ago.year }.sample
    month = months.to_a.sample
    days   = options[:days]   || (1..Date.civil(year, month, -1).day)
    day = days.to_a.sample

    Date.new(year, month, day)
  end

end