Ab Abd Allah Muammad ibn Jabir ibn Sinan al-Raqq al-arran al-abi al-Battan (Latinised as Albategnius, Albategni or Albatenius) (c. 858, Harran - 929, Qasr al-Jiss, near Samarra) was a Muslim astronomer, astrologer, and mathematician. Little is known about al-Battan's life beside that he was born in Harran near Urfa, in Upper Mesopotamia, which is now in Turkey, and his father was a famous maker of scientific instruments. One of al-Battan's best-known achievements in astronomy was the determination of the solar year as being 365 days, 5 hours, 46 minutes and 24 seconds. Read more