Sizdah be dar is a the last day of Norooz, the Iranian New Year, a celebration that comes from Persian roots and is focused on bringing good luck into the home for the coming year. On Sizdah be dar, the 13th day of the New Year, it is the custom to leave the house for the entire day because in Iranian culture 13 is an unlucky number and so they want to be outside the house. Seezdah means 13 and Bedar means away or out. Most folks have day-long picnics outside or attend events staged in parks. They also throw pieces of sabzeh (sprouted wheat or lentils) into a river to wash away the bad luck. It is a custom to tie pieces of grass together and to make a wish for the coming year.