Yes there is.
I edit YAF 1.9.3 RC2 to work with Persian calendar and I just finished editing YAF 1.9.4 Beta2 to work with persian calendar.
All you have to do is to use "FarsiLibrary" class written by Mr. Hadi Eskandari and do some coding in YafDateTime.cs file in YAF.Classes.Core.Services.
If you have any further questions, I'd be glad to help.
Here's a link to the "FarsiLibrary" class.
http://www.hightech.ir/SeeSharp/farsilibrary-21-released
If at first you don’t succeed, call it version 1.0