Lie of the Thirteen (دروغ سیزده – Doruq e Sizda') is the Iranian version of the prank-playing April Fools' Day which is practiced on the first or the second day of April in Iran, on the day of Sizdah Be-dar.
A ritual performed at the end of the picnic is to throw away the greenery (سبزه – Sabze) collected for Haft-Seen, the customary setting of Nowruz in Iran. Touching someone else's greenery on this day or bringing it back home is considered a bad omen.
Chahardah Be-dar (Persian: Čahārda' be Dar – چهارده به در) is the fourteenth day of Nowruz, which is celebrated only in Lorestan Province. Lurs stay home on the thirteenth day of Nowruz, referred to as the Strange Thirteen (سیزده غریب – Sizdah e Qarib) by them. Instead, they picnic outdoors a day after Sizdah Be-dar.