Nowruz is the most important and the oldest tradition of Iranians observed by even those who were once the nationals of Persia, an empire bigger than what is the size of Iran of today. March 21st is in the most cases the first day of the Iranian calendar year called Nowruz which literally means a new day.
It matters a lot to Iranians as it both marks the beginning of the New Year and at the same time the new agricultural year which is very explicitly felt by the scene of newly greened trees, the fresh turf, and the budding flowers.
In Iranian northern Province of Gilan, a trio of singers drop in on doors and sing a short folklore song marking the event and wishing good things for their fellow villagers. In return, it is customary for the householders to give the singers gifts or to offer them sweets, candies, eggs, peas, and other foods.
Nowruz celebration is observed in Iran, Albania, Afghanistan, Azerbaijan, China (by Turkic peoples and Tajiks), Georgia, India (by Parsis), Iraq (by Kurds and Turkmens), Kazakhstan, Kyrgyzstan, Pakistan, Russia, Syria (by Kurds), Tajikistan, Turkey, Turkmenistan, and Uzbekistan.