Date not correctly show in Jalali calendar in (persian or farsi) language

Hi
I instal icagenda in joomla with jalali calendar, every thing is ok but date in calendar module not show correctly! for example: May 12, 1980 is monday but in jalali calendar (Ordibehesht 22, 1359) show in Wednesday!
How can I solve this problem?
Thank you.

Hello again
Unfortunately, this problem has not been fixed in the new updates!
The Jalali calendar is widely used in the Middle East region, but the "calendar display module" does not support it and displays dates based on the Gregorian calendar!
To check this issue, you need to add the Persian language to Joomla and set it as the default language, then display the calendar module in this language.
I have attached the official and verified PHP code file for converting the Gregorian calendar to Jalali.
But I don't know how to add this code to the source of calendar display module to solve this problem!
I request you, if it is possible, add this code in the source of the icagenda calendar in new updates, so that whenever the Persian language is selected, this calendar will be executed automatically.
Thank you