The whole date.
I mean I want to add totally new calendar.
I mean: Gregorian to Jalali (Jalali or Shamsi is official calendar of Iran. I have a php file containing everything needed to convert Gregorian to Jalali. But I don't know what should be done with xenforo to add new calendar to it. For example when we add Farsi lanuage and we set it to be RTL, we become able to set Jalali as the date of system.)