Thank you for contacting Syncfusion support.
By default, when a cell is double clicked, local time will be shown in the appointment window. When an appointment is saved, Scheduler saves an appointment with the universal time (with UTC as 0) in the database which is the default behavior. If we have misunderstood your requirement kindly share the following information with us to proceed further.
1. Code example/sample (if possible).
2. Image or vide demo explaining your requirement.
Regards,
Karthigeyan