Converting between the Solar Hijri and Gregorian calendars is not a straightforward arithmetic problem. It requires an understanding of their different leap year rules and epochal offsets. The difference in year values between the two calendars is ; it fluctuates depending on the specific date, shifting between a difference of 621 and 622 years.
هر چهار سال یکبار، یک روز به تقویم اضافه میشود. tarikh shamsi b miladi