Why can this date be set to holiday?

Why can this date be set to holiday?
I set the start date by inline editing.
It can be set to display on holidays


https://snippet.dhtmlx.com/zjst3nlr

Hello,
When the correct_work_time config is enabled, Gantt snaps the task’s start date to the working time. But this works only when you drag tasks:


https://docs.dhtmlx.com/gantt/api__gantt_correct_work_time_config.html

If you want to have the same functionality in the lightbox and inline editors, you need to implement a custom solution.
The following snippet can help you to start implementing your solution: