Jalali calendar is a small and portable free software library to manipulate date and time in
system. It's written in C and has absolutely zero dependencies.
It works on top of any POSIX.1-2001 (and later) compatible libc implementations.
Jalali calendar provides an API similar to that of libc's timezone, date and time
Jalali calendar package consists of a library namely libjalali and two simple and easy to use terminal tools, jcal and jdate with functionality similar to UNIX cal and date.
You can always obtain the latest version of Jalali calendar or else, all releases from here. If you encountred any problems with downloading source tarballs, you can obtain them from this mirror.
Alternatively consider cloning project's git repository. A web interface to that git repository is also available. This project is also available on github.
Fetch latest Jalali calendar gentoo ebuilds from here.
To get familiar with libjalali's API and function sets, please consult it's documentation. The use of jstrftime() and jstrptime() functions are explained in detail here and here.
Take a look at jcal and jdate manual pages. A small set of examples and test-kits to work with Jalali calendar library is available here.
Please file your bug reports to <ghassemi AT ftml dot net>.