(1)      Whenever Titles 1 through 10 of this article require any action to be taken within a reasonable time, any time which is not manifestly unreasonable may be fixed by agreement.

      (2)      What is a reasonable time for taking any action depends on the nature, purpose and circumstances of such action.

      (3)      An action is taken "seasonably" when it is taken at or within the time agreed or if no time is agreed at or within a reasonable time.