For our Mahdi, there are two signs which have never appeared before, since the creation of the heaven and earth, namely, the moon will be eclipsed on the first night in Ramadhan (on the first of its appointed nights of eclipse), and the sun will be eclipsed on the middle day of Ramadhan (middle of the appointed days of eclipse). And these signs have not appeared since the creation of heaven and earth. (Saying of the Holy Prophet of Islam "Darqutni")