An Iranian National Nature Day, locally known as �Sizdah Be-dar�, is held on the 13th day of Farvardin (the first month of the Iranian calendar) to bid farewell to the Nowruz holidays.

The celebration of Nowruz needs a happy ending to make it perfect, so on the last day of this celebration people go outdoors to celebrate the end of the Nowruz holidays.

On the 13th day of Farvardin, which falls on April 2 in normal years and April 1 in leap years, every Iranian people try to spend and enjoy this day in the best possible way.