Introduction:
Nowruz is the beginning day of spring and the first day of the month of Farvardin, which marks the beginning of the Solar Hijri calendar. The celebration of Nowruz is attributed by some scholars to ancient Iranian kings and is considered by others a Zoroastrian practice. Others simply regard it as an Iranian national tradition and the most ancient symbol of Iranian culture.
Nowruz is also introduced as an indication of pluralistic Persian culture that contributed to the peaceful coexistence among various people. It is a holiday that brings together Zoroastrians, Christians, Sunnis, and Shiites, despite all their differences, on the Haft-Sin table (a table with seven items whose names in Persian start with “sin” or s sound, which is arranged for the celebration of Nowruz).
Rulers used to receive gifts and taxes from people on Nowruz. In some periods, the appointment of officials to their positions would be arranged on this day.
In addition to Iran, Nowruz is celebrated in other countries, including Tajikistan, Afghanistan, Pakistan, Azerbaijan, Kirgizstan, Uzbekistan, Kazakhstan, and Zanzibar.
The United Nations has officially recognized Nowruz as the “International Nowruz Day.”
Traditions and Customs:
The celebration of Nowruz has included a series of traditions and customs. Iranians begin to prepare themselves for Nowruz days or even weeks ahead. They clean their houses and wear new clothes. They plant greenery for their tables of Haft-Sin and preserve it until the thirteenth day of Farvardin when they throw it to a river or a stream.
Arranging the Haft-Sin table is also a Nowruz custom, whose symbolic meaning has been variously explained. Iranian Muslims also place the Quran on their Haft-Sin table.
Giving and receiving gift, usually in the form of money, is an ancient Nowruz custom. Colored eggs are also among the gifts that are exchanged on Nowruz.
Visiting relatives and friends is a widely common tradition during Nowruz holidays.
Many people prefer to be present in a sacred place at the moment of the beginning of the new year.
Travelling is also very common on Nowruz holidays.
Reference: https://en.wikishia.net/view/Nowruz