Avoid selecting more than one date

Hello, How to avoid selecting more than one date?
The users can only create a single day event.

do you mean remove second date selector from the lightbox? If so, the only way to do so is hide unneeded selectors via display:none. For example, remove end date selectors completely: scheduler.attachEvent("onLightbox", function(){ var node = scheduler.formSection("time").node; var sels = node.getElementsByTagName("select"); var start = sels.length - 4;//'end_date' inputs sels[start].previousSibling.style.display='none';//hide 'dash' for (var i=start; i<sels.length; i++) sels[i].style.display="none";//hide selects });
If you mean more general validation for event durations, you can use onEventSave and onBeforeEventChanged events. They allows checking event state and altering or preventing changes when necessary
docs.dhtmlx.com/scheduler/api__s … event.html
docs.dhtmlx.com/scheduler/api__s … event.html