Changing the date system from Gregorian to Solar

[EsmitJonz]

Describe the feature

Hi
I wanted to change the entire date system from Gregorian to Solar. Do you have any suggestions on this?
For example, it should change in relation to changing the time zone.

Or it would be great if you could tell me which part I should change for this.

[EsmitJonz]

For example, this is a pre-written code sample
but I don't know how to use it in your code

https://github.com/jalaali/jalaali-php
https://github.com/roozbeh360/Gregorian-Jalali-Date-Convertor
https://stackoverflow.com/questions/76551635/convert-gregorian-date-to-solar-in-wordpress
https://www.codeproject.com/Articles/28380/Persian-Calendar-in-PHP