method

change

v6.1.7.7 - Show latest stable - 0 notes - Class: DateTime

change(options) public

Returns a new DateTime where one or more of the elements have been changed according to the options parameter. The time options (:hour, :min, :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. The options parameter takes a hash with any of these keys: :year, :month, :day, :hour, :min, :sec, :offset, :start.

DateTime.new(2012, 8, 29, 22, 35, 0).change(day: 1)              # => DateTime.new(2012, 8, 1, 22, 35, 0)
DateTime.new(2012, 8, 29, 22, 35, 0).change(year: 1981, day: 1)  # => DateTime.new(1981, 8, 1, 22, 35, 0)
DateTime.new(2012, 8, 29, 22, 35, 0).change(year: 1981, hour: 0) # => DateTime.new(1981, 8, 29, 0, 0, 0)

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# File activesupport/lib/active_support/core_ext/date_time/calculations.rb, line 51
  def change(options)
    if new_nsec = options[:nsec]
      raise ArgumentError, "Can't change both :nsec and :usec at the same time: #{options.inspect}" if options[:usec]
      new_fraction = Rational(new_nsec, 1000000000)
    else
      new_usec = options.fetch(:usec, (options[:hour] || options[:min] || options[:sec]) ? 0 : Rational(nsec, 1000))
      new_fraction = Rational(new_usec, 1000000)
    end

    raise ArgumentError, "argument out of range" if new_fraction >= 1

    ::DateTime.civil(
      options.fetch(:year, year),
      options.fetch(:month, month),
      options.fetch(:day, day),
      options.fetch(:hour, hour),
      options.fetch(:min, options[:hour] ? 0 : min),
      options.fetch(:sec, (options[:hour] || options[:min]) ? 0 : sec) + new_fraction,
      options.fetch(:offset, offset),
      options.fetch(:start, start)
    )
  end

change

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