On which Solar Hijri date is Sizdah Bedar traditionally celebrated?

Sizdah Bedar is traditionally celebrated on 13 Farvardin, the thirteenth day of the Solar Hijri year.

It is the closing day of the Nowruz holiday period in Iran. Families commonly spend the day outdoors, visiting parks or countryside areas, eating together and enjoying games. The phrase “Sizdah Bedar” is commonly interpreted as referring to getting outdoors on the thirteenth day.

A well-known custom is taking the sabzeh, the sprouted greenery displayed during Nowruz, outside and returning it to flowing water. In popular practice, young people may also tie the sprouts before releasing them, although customs vary by region and family.

Sizdah Bedar is sometimes called Nature Day in English. Its date is fixed in the Solar Hijri calendar, so its Gregorian date shifts slightly from year to year.