I have a customer who requires to be able to create events from the lightbox with a duration that can only be 2 hours, 2.5 hours, 3 hours, 3,5 hours and 4 hours. While there are not strict limitations on the starting time of this lesson.
What I would like to achieve then is that the ending time dropdown shuld only contain the ening time that are compatible with the requested durations.
For example if the lesson starts at 8am, end time sropbox should only contain 10:00, 10:30, 11:00, 11:30, 12:00.
Unfortunately, there is no easy way to limit the options of end_time section in the lightbox as you need. You can do it by updating scheduler.form_blocks.time in the source code:
As an alternative solution, try using onEventSave handler to check the duration before saving the lightbox and show the message that the user must update the duration if it is > 3.5h. Please check the snippet that demonstrates how it can be implemented: http://snippet.dhtmlx.com/24f4905fe