If your model is :timestamped, it will automatically set the
:created_at and :updated_at columns if they exist

With a migration like:

class MessageMigration < Sequel::Migration
  def up
    create_table :messages do
      primary_key :id
      integer :user_id
      string :name
      boolean :direct
      datetime :created_at
      datetime :updated_at
    end
  end

  def down
    execute "DROP TABLE messages"
  end

end

a class with

class Message < Sequel::Model
  is :timestamped
  belongs_to :user
end

will be autotimestamped