Aries: 6-8 hours.
Taurus: 46 hours.
Gemini: either 4 or 12 , there's no in between.
Cancer: 10 hours.
Leo: a solid 8 hours.
Virgo: 9 hours, but don't try to wake them up before.
Libra: 7.5 hours.
Scorpio: 30 min nap and they're good.
Sagittarius: sleep is for the dead.
Capricorn: 4 hours.
Aquarius: 5 on
Pisces: 2-3 hours.