Sizdah’ means thirteen, and ‘Bedar’ means to get rid of, bearing the meaning of ‘getting rid of thirteen’. Sizdah Bedar also marks the end of Nowruz celebrations, which begin on the first day of spring.

The 13th day of every month in the Persian calendar is called “Tir Ruz,” which is “named after Tishtrya, the star associated with rainfall.” It is believed that Jamshid, a mythological king of Iran, established Nowruz and the tradition of Sizdah Bedar so that people could spend time in the green nature under canopies and in the company of the people, every year.

It is customary for Iranian families to go for a picnic, taking the green shoots grown for Nowruz and releasing them into a stream or river in celebration of the ancient festival.

On the eve of Sizdah Bedar, many typically think about choosing an appropriate place to spend the day. Some choose parks, some go to the countryside and others come together in a garden to celebrate the day. Usually, several families plan to gather in a place to spend the day outdoors. It is believed that joy and laughter clean the mind from all evil thoughts, and a picnic is usually a festive, happy event.

One interesting tradition on Nature Day is tying knots in the grass, which symbolizes the strengthening of relationships between life and nature, as well as fulfilling one’s wishes.

People spend the day playing traditional games, singing and listening to music, chatting, or simply resting along the banks of the river. They also eat lettuce with sekanjebin (a traditional Iranian drink) and cook local foods. The joy of the day is supposed to ward off an evil that the unlucky number thirteen might bring along with it.