Lahore, March 20 -- Nowruz is the Iranian New Year, also known as the Persian New Year, which is celebrated worldwide by various ethno-linguistic groups. Nowruz is the day of the vernal equinox, and marks the beginning of spring in the Northern Hemisphere. It marks the first day of the first month (Farvardin) of the Iranian calendars. It usually occurs on March 21 or the previous or following day, depending on where it is observed. The moment the Sun crosses the celestial equator and equalizes night and day is calculated exactly every year, and families gather together to observe the rituals. While Nowruz has been celebrated since the reform of the Iranian Calendar in the 11th Century CE to mark the New Year, the United Nations officially r...