+

Adds an interval of time to the current object’s time and returns that value as a new TimeWithZone object.

Time.zone = 'Eastern Time (US & Canada)' # => 'Eastern Time (US & Canada)' now = Time.zone.now # => Sun, 02 Nov 2014 01:26:28.725182881 EDT -04:00 now + 1000 # => Sun, 02 Nov 2014 01:43:08.725182881 EDT -04:00 

If we’re adding a Duration of variable length (i.e., years, months, days), move forward from #time, otherwise move forward from #utc, for accuracy when moving across DST boundaries.

For instance, a time + 24.hours will advance exactly 24 hours, while a time + 1.day will advance 23-25 hours, depending on the day.

now + 24.hours # => Mon, 03 Nov 2014 00:26:28.725182881 EST -05:00 now + 1.day # => Mon, 03 Nov 2014 01:26:28.725182881 EST -05:00