Hi Ahmed,
Thank you for your interest in Syncfusion products.
Please try using WeekCalendarStartDayOfWeek property in appearance to solve this misbehavior.
scheduleControl.Appearance.WeekCalendarStartDayOfWeek = DayOfWeek.Sunday;
1. Could you please update us a minimal sample that depicts the issue, so that we can provide you the solution at the earliest.
2. Normally the Workweek started with Monday. If you want to change, then please try to select the Dates in NavigationCalendar to show the WorkWeek.
3. I am afraid that I am not able to see the issue in Scheduler control when the control customized in Designer view.
Refer the sample from below link:
http://files.syncfusion.com/samples/Grid.Windows/Forums/F89696/Schedule.zipPlease have a look at the above sample and if still the issue exists, could you please try reproducing it in the above sample or send us the reproducing steps so that we could sort out the cause of the issue and provide you a solution?
Regards,
Lingaraj S.