The Solar Hijri calendar is the official calendar of Iran. It is only used in Iran and Afghanistan. The name of the calendar is abbreviated as SH. It is also called the Solar Hejri calendar^[1] and (Persian: گاه‌شماری هجری خورشیدی, romanized: gāh-shomāri-ye hejri-ye khorshidi; Pashto: لمريز لېږدیز کلیز).

Its year begins on the March equinox (Nowruz) at the Iranian standard meridian (52.5°E, UTC+03:30). Each year is 365 or 366 days long.

Each of the twelve months corresponds with a zodiac sign. The first six months have 31 days, the next five have 30 days, and the last month has 29 days in usual years but 30 days in leap years. Its New Year's Day (1 Nowruz) always falls on the March equinox.