The Iranian calendar Persian: گاه شماری هجری خورشيدى also known as Persian calendar or the Jalāli Calendar is a solar calendar. It is currently used in Iran and Afghanistan. It is observation-based, rather than rule-based. Each year starts on the vernal equinox as precisely determined by astronomical observations from Tehran (or the 52.5°E meridian, which also defines IRST) and Kabul. This makes it more accurate than the Gregorian Calendar.
The current Iranian Calendar year is 1400AP (AP = Anno Persico/Anno Persarum = Persian year).