The Power of Twelve

There are:
12 inches in a foot
12 months in a year
12 times 2 = 24 hours in a day
12 times 5 = 60 minutes in an hour
12 times 30 = 360 degrees in a circle
12 times 10 = 120 beats per minute, the standard military marching pace
12 times 10 = 120, the optimum systolic blood pressure
12 volts in automobile electrical systems
12 was the base for early mathematics

There are also:
12 grades in the American school system
12 signs of the zodiac
12 items in a dozen
12 pence in a shilling
12 people on a jury
12 tribes of Israel
12 apostles in Christianity, which borrowed the idea from
12 apostles in Mithraism
12 days to the Christmas season, from Yule to Epiphany
12  parts to the Boy Scout Law (Trustworthy, loyal, etc.)
12 steps to humility (St. Benedict, 520 A.D.)
12 steps of pride (St. Bernard of Clairveaux, 1130 A.D.)
12 steps to sobriety (Bill Miller, founder of AA, 1937)
12 original Bill of Rights Amendments to the U.S. Constitution
 -- Proposed in 1789, in force by 1791
--  Proposed amendments One and Two were not ratified promptly, so Three through Twelve became the Bill of Rights as we know it today
-- Proposed Amendment One was ratified in 1992 as Amendment 27, concerning Congressional pay hikes
-- Connecticut, Massachusetts, Georgia did not ratify the Bill of Rights until 1939.