Prevent Event Overlap
Sometimes it is necessary to guarantee that events don't overlap - eg. when scheduling workorders, interacting with a work calendar. You can reject the updates or additions and let the user know about it.
The event overlap can be turned on/off on an event basis, per resource or globally on the instance.
- On an event basis - by setting the
overlapproperty tofalsethe specified event cannot overlap. - Per resource - by setting the
eventOverlapproperty tofalsethe events in the specified resource cannot overlap. - Globally on the instance - by setting
eventOverlapoption tofalseoverlap is disbled globally.
If set to false, the resource and the event settings have precedence over the global calendar eventOverlap option.
Give feedback to the user - optionally, a toast can be displayed to explain why an event cannot be dropped, moved or created. For this we can use the onEventCreateFailed and onEventUpdateFailed lifecycle events.
Demo
eventOverlap=falsemobiscroll.eventcalendar('#calendar', {
view: {timeline: { type: 'day' }},
// relevant events
data: [{
start: '2026-10-23T16:00',
end: '2026-10-23T18:00',
title: 'Event 2 (no event overlap)',
overlap: false,
resource: 1
},{
start: '2026-10-23T08:00',
end: '2026-10-23T10:00',
title: 'Event 4 (no event overlap)',
overlap: false,
resource: 2
}],
// relevant resource
resources:[{
id: 4,
name: 'Resource 4 - no event overlap allowed',
eventOverlap: false
}],
dragToMove: true,
dragToResize: true,
clickToCreate: true,
dragToCreate: true,
eventOverlap: true
});

mobiscroll.setOptions({
locale: ,
theme: ' ',
themeVariant: ' '
});
function onEventFailed() {
mobiscroll.toast({
message: 'Make sure not to double book',
});
}
var now = new Date();
var y = now.getFullYear();
var m = now.getMonth();
var d = now.getDate();
mobiscroll.eventcalendar('#demo', {
view: {
timeline: { type: 'day' },
},
clickToCreate: true,
dragToCreate: true,
dragToMove: true,
dragToResize: true,
eventOverlap: true,
data: [
{
start: new Date(y, m, d, 11),
end: new Date(y, m, d, 13),
title: 'Event 1',
resource: 1,
},
{
start: new Date(y, m, d, 16),
end: new Date(y, m, d, 17),
title: 'Event 2 (no event overlap)',
overlap: false,
resource: 1,
},
{
start: new Date(y, m, d, 14),
end: new Date(y, m, d, 16),
title: 'Event 3',
resource: 2,
},
{
start: new Date(y, m, d, 8),
end: new Date(y, m, d, 10),
title: 'Event 4 (no event overlap)',
resource: 2,
overlap: false,
},
{
start: new Date(y, m, d, 10),
end: new Date(y, m, d, 13),
title: 'Event 5',
resource: 3,
},
{
start: new Date(y, m, d, 11),
end: new Date(y, m, d, 16),
title: 'Event 6',
resource: 4,
},
],
resources: [
{
id: 1,
name: 'Resource 1',
},
{
id: 2,
name: 'Resource 2',
},
{
id: 3,
name: 'Resource 3',
},
{
id: 4,
name: 'Resource 4 - no event overlap allowed',
eventOverlap: false,
},
],
onEventUpdateFailed: onEventFailed,
onEventCreateFailed: onEventFailed,
});
<div id="demo"></div>