Mongoid currently uses Time.now or Time.now.utc for setting timestamps:

lib/mongoid/timestamps/created.rb:          time = Time.now.utc
lib/mongoid/timestamps/updated.rb:          self.updated_at = Time.now.utc unless updated_at_changed?
lib/mongoid/touchable.rb:        current = Time.now

This is counter to our documentation (https://www.mongodb.com/docs/mongoid/master/reference/configuration/#time-zones) in which we recommend using Time.zone.now.

I think Time.zone.now is the correct usage (I also don't understand the reason for explicit conversion to UTC).