How it works
Pick a number between 1 and 12 with one press. A year has 12 months, a clock face 12 hours and a d12 has 12 sides, so one pick can stand for any of them: 7 is July, 7 o'clock or a roll of 7. Switch repeats off to shuffle all 12.
Read the full guide
Pick a number 1-12 and read it as a month or an hour
Count from January: 3 is March, 9 is September, 12 is December. Months 1, 3, 5, 7, 8, 10 and 12 have 31 days, so the pick tells you the length too. For a clock, settle on morning or evening before you press. If 12 comes up, say noon or midnight: by convention 12 p.m. is noon, but style guides advise the plain words.
A d12 roll, which is not two dice
A twelve-sided die is a dodecahedron: 12 faces, each a regular pentagon, numbered so that a face and the one opposite usually total 13. Pick a number 1 through 12 here and you have rolled one. Two six-sided dice are different: their total is never 1 and lands on 7 far more often than on 12. For those, open pick a number 1-6 and ask for 2.
- A dozen splits more ways than ten: 2 teams of 6, 3 of 4, 4 of 3 or 6 pairs. Draw all 12 with repeats off and cut the list.
- For a year of book club hosts, number the members, draw 12 with repeats off and read down from January.
- For a 24-hour time, tap 'Hours 0 to 23', then 'Minutes 0 to 59': 17 then 5 is 17:05. '1 to 12' puts the page back.
Questions and answers
Is this a fair way to choose a month?
Yes, and fairer than drawing a random date, which lands in the 31-day months more often. Here every month has one chance in 12, about 8.3%. The pick is made in your browser: fine for games and family plans, not for a draw with money at stake.
Why did I get the same month twice?
Repeats are on when the generator opens, as on a real die: a press has no memory of the one before. For 12 different numbers, say a gift swap order for a family of 12, set how many to 12 and switch repeats off.
How old is the habit of counting hours in twelves?
Very old. The 12-hour clock goes back to Mesopotamia and ancient Egypt: an Egyptian sundial and a water clock from about 1500 BC each split their time of use into 12 hours. The letters a.m. and p.m. stand for the Latin for before and after midday.