to reproduce this bug : add RadDateTimePicker and set culture to fa-IR change the header navigation mode to zoom with : Me.radDateTimePicker1.DateTimePickerElement.Calendar.HeaderNavigationMode = HeaderNavigationMode.Zoom popup the date time picker then georgian dates are displayed i'll attach screenshots of what happening.
Merged with: https://feedback.telerik.com/Project/154/Feedback/Details/225911-fix-raddatetimepicker-the-year-is-not-correct-when-one-is-using-persian-cultur