Method: Time#change

Defined in:
lib/active_support/core_ext/time/calculations.rb

#change(options) ⇒ Object

Returns a new Time where one or more of the elements have been changed according to the options parameter. The time options (:hour, :min, :sec, :usec, :nsec) reset cascadingly, so if only the hour is passed, then minute, sec, usec and nsec is set to 0. If the hour and minute is passed, then sec, usec and nsec is set to 0. The options parameter takes a hash with any of these keys: :year, :month, :day, :hour, :min, :sec, :usec :nsec. Pass either :usec or :nsec, not both.

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



118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
 
# File 'lib/active_support/core_ext/time/calculations.rb', line 118

def change(options)
  new_year  = options.fetch(:year, year)
  new_month = options.fetch(:month, month)
  new_day   = options.fetch(:day, day)
  new_hour  = options.fetch(:hour, hour)
  new_min   = options.fetch(:min, options[:hour] ? 0 : min)
  new_sec   = options.fetch(:sec, (options[:hour] || options[:min]) ? 0 : sec)

  if new_nsec = options[:nsec]
    raise ArgumentError, "Can't change both :nsec and :usec at the same time: #{options.inspect}" if options[:usec]
    new_usec = Rational(new_nsec, 1000)
  else
    new_usec = options.fetch(:usec, (options[:hour] || options[:min] || options[:sec]) ? 0 : Rational(nsec, 1000))
  end

  if utc?
    ::Time.utc(new_year, new_month, new_day, new_hour, new_min, new_sec, new_usec)
  elsif zone
    ::Time.local(new_year, new_month, new_day, new_hour, new_min, new_sec, new_usec)
  else
    raise ArgumentError, "argument out of range" if new_usec >= 1000000
    ::Time.new(new_year, new_month, new_day, new_hour, new_min, new_sec + (new_usec.to_r / 1000000), utc_offset)
  end
end