How to limit minimum possible date/time in jtsage datetimebox?

Question

anybody knows or has an example of how to set limitation of minimum allowed datetime in the datetimebox in jtsage script?

My case is the following - I have a form where user enters tennis game, and there are two date/time related fields: GameStart and GameEnd.

Once the user sets GameStart (which can be any time in the future), for example 2018-02-25 13:00, I would like to limit the GameEnd minimum to the same date/time as the user has selected as GameStart. In this particular example user should not be able to set datetime lower than 2018-02-25 13:00.

To put it in other words, user cannot select GameEnd before GameStart. Makes sense, right?

I have a callback JavaScript function, which triggers just fine, reads the GameStart ad datetime object. But once I set min and applyMinMax, it just doesn't work.

This is my code:

            var minDate = $('#GameStarts').datebox('getTheDate');
            $('#GameEnds').attr('min', minDate);
            $('#GameEnds').datebox('applyMinMax');

Any idea?