It is impossible to override the default week calculation

[reestyle-it]

It is impossible in the current code to override the default custom week calculation (or any prototype for that matter) because it is set each time on rendering.

Preferably the prototyping is NOT done on rendering, because that would override the new 'custom' override.

It should be done before applying the plug-in to jQuery (e.g. before $.fn.gantt = function (options) { ).

Because it is already a custom prototype function, there is no functional need to re-apply it every time other than that you want the default version to be the only truth...