Shani dev (Sanskrit: शनि, Śani) is one of the Navagraha (the nine primary celestial beings in Hindu astrology) of Jyotiṣa. Shani dev is embodied in the planet Saturn and is the Lord of Saturday. Shani dev is also known as Śanaiścara (शनैश्चर). The word shani also denotes the seventh day or Saturday in most Indian languages. The word shani (शनि) comes from Śanayē Kramati Saḥ (शनये क्रमति सः), the one who moves slowly, because Saturn takes about 30 years to orbit the Sun.