Shamsi

Shamsi, also known as the Solar Hijri calendar, is the official calendar used in Iran and Afghanistan. It is a solar calendar that bases dates on the Earth's orbit around the Sun, beginning each year at the vernal equinox (around March 21). Unlike the Gregorian calendar, which has fixed months, the Shamsi calendar's new year, Nowruz, shifts slightly each year but generally falls around March 21. It consists of 12 months, with the first six months having 31 days, the next five months 30 days, and the last month 29 or 30 days. It aligns closely with natural seasons and is culturally significant in the region.