In Rails 5.2, when one generates a model using rails g model foo, the model gets the timestamps added by default to it in the generated migration.

Mongoid by default currently does not add timestamps by adding include Mongoid::Timestamps to the model. This behavior can be requested by specifying --timestamps option to rails g model.

To be consistent with Rails/ActiveRecord, Mongoid will also enable timestamps by default. The legacy behavior can be obtained by passing --no-timestamps to rails g model.