Bookem allows you to reschedule, edit or cancel bookings as needed.
Follow these steps:
Go to your Calendar
Navigate to the booking you'd like to edit
Now, you can either drag and drop a booking directly or click on it to edit
If you click on it, you can edit the time and date manually
Now, before saving, you can decide if you want the client to be notified of changes made or not
If you don't want to send a notification click on the arrow next to the save button:
When cancelling a booking, you can untick the send notifications button: