Yaldā, another nationally celebrated ancient tradition, commemorates the ancient goddess Mithra and marks the longest night of the year on the eve of the winter solstice (; usually falling on 20 or 21 December), during which families gather together to recite poetry and eat fruits—particularly the red fruits watermelon and pomegranate, as well as mixed nuts. In some regions of the provinces of Mazanderan and Markazi, there is also the midsummer festival of Tirgān, which is observed on Tir 13 (2 or 3July) as a celebration of water.