(Κλεόστρατος), an astronomer of Tenedos. Censorinus (de Die Nat. 100.18) considers him to have been the real inventor of the Octaeteris, or cycle of eight years, which was used before the Metonic cycle of nineteen years, and which was popularly attributed, to Eudoxus. Theophrastus (de Sign. Pluv. p. 239, ed. Basil. 1541) mentions him as a meteorological observer along with Matricetas of Methymna and Phaeinus of Athens, and says that Meton was taught by Phaeinus. If, therefore, Callistratus was contemporary with the latter, which however is not clear, he must have lived before Ol. 87. Pliny (Plin. Nat. 2.8) says, that Anaximander discovered the obliquity of the ecliptic in Ol. 58, and that Cleostratus afterwards introduced the division of the Zodiac into signs, beginning with Aries and Sagittarius. It seems, therefore, that he lived some time between B. C. 548 and 432. Hyginus (Poet. Astr. 2.13) says, that Cleostratus first pointed out the two stars in Auriga called Haedi. (Verg. A. 9.668.) On the Octaeteris, see Geminus, Elem. Astr. 100.6. (Petav. Uranolog. p. 37.)

(Ideler, Technische Chronologie, vol. i. p. 305; Schaubach, Gesch. d. Gr. Astron. p. 196; Petavius, Doctr. Temp, 2.2; Fabric. Bibl. Graec. vol. ii. p. 82.)