Active Record Timestamp

Active Record automatically timestamps create and update operations if the table has fields named created_at/created_on or updated_at/updated_on.

Timestamping can be turned off by setting:

config.active_record.record_timestamps = false

Timestamps are in UTC by default but you can use the local timezone by setting:

config.active_record.default_timezone = :local

Time Zone aware attributes

Active Record keeps all the datetime and time columns timezone aware. By default, these values are stored in the database as UTC and converted back to the current Time.zone when pulled from the database.

This feature can be turned off completely by setting:

config.active_record.time_zone_aware_attributes = false

You can also specify that only datetime columns should be time-zone aware (while time should not) by setting:

ActiveRecord::Base.time_zone_aware_types = [:datetime]

You can also add database-specific timezone aware types. For example, for PostgreSQL:

ActiveRecord::Base.time_zone_aware_types += [:tsrange, :tstzrange]

Finally, you can indicate specific attributes of a model for which time zone conversion should not applied, for instance by setting:

class Topic < ActiveRecord::Base
  self.skip_time_zone_conversion_for_attributes = [:written_on]
end

activerecord/lib/active_record/timestamp.rb