Install hijra-applet by entering the following commands in the terminal:
sudo apt update sudo apt install hijra-applet
Description:
Hijri Islamic Calendar tray applet and GNOME shell extension
Hijri Tray Applet for GNOME (also works with KDE), and GNOME shell extension that uses Hijra Algorithm by Muayyad Saleh Alsadi provided by python-hijra package. . This algorithm is based on integer operations which that there is no round errors (given accurate coefficients) the accuracy of this algorithm is based on 3 constants (p, q and a) where p/q is the full months percentage [ gcd(p,q) must be 1 ] currently it is set to 191/360 which mean that there is 191 months having 30 days in a span of 360 years, other months are 29 days, and a is just a shift.
Homepage: http://hijra.ojuba.org
Version: 0.4.1-1
Section: multiverse/misc