Because a new decan also appears heliacally every ten days (that is, every ten days, a new decanic star group reappears in the eastern sky at dawn right before the Sun rises, after a period of being obscured by the Sun's light), the Greeks called them dekanói (; pl. of ??????? dekanós) or "tenths".

Decans gave way to a lunar division of 27 or 28 lunar stations, also known as manzil , lunar stations, or nakshatras