Thank you for writing back.
My previous reply was not for this thread. Please accept my apologies for the mistake.
Regarding your question, if you want a Persian calendar, you will have to use a custom one or implement it yourself since our controls support only Gregorian calendar.
The current culture determines only the way the days of the week and the month are displayed. It does not change the layout of the RadCalendar. If you have issues setting the current culture to Iran's culture and displaying the dates according to it, please refer to the attached project.
If you decide to go with different calendars, you might find those links helpful: link
As to your other thread, please note that we do support our customers within 72 hours (Mon-Fri) for forum threads and within 24-48-72 hours for support tickets (depending on the license that you have). In order to receive such a support, please provide the details requested in thread "How to combine two fields into one single field?"
Please have in mind that not providing license information may lead to a denial of support services for your account.
I hope this helps.
the Telerik team
Q3’10 SP1 of RadControls for WinForms is available for download
; also available is the Q1'11 Roadmap
for Telerik Windows Forms controls.