Timestamps

with_timestamps macros adds callbacks for created_at and updated_at fields update. But now they still should be defined in the mapping manually:

class MyModel < Jennifer::Model::Base
  with_timestamps

  mapping(
    id: Primary32,
    created_at: {type: Time, null: true},
    updated_at: {type: Time, null: true}
  )
end

created_at field is populated with current time when corresponding record is stored to the database. updated_at - whenever record is updated (the way that callbacks are invoked).