Marut:
Check the Sun Settings. Check the
Detailed Settings box, then go to Environment > Physical Sky > Time and Location and check these settings (Use ArchiCAD's Sun Position or correct the Day and Time and Location).
You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.
David