# What are the odds? [Question about a birthday falling on Chinese New Year]

Today is my birthday. It’s also Chinese New Years. It’s also my Chinese Zodiac year (rat)! I was wondering what the statistical odds are for this to occur. I suck at stats.

Also, happy birthday to me!

Oh fudge. I didn’t really title this well. Could a mod please perhaps add - Auto’s birthday, or maybe “a birthday question”

As far as I know, Chinese New Year has to fall on some date around Jan 20-Feb 20 every year (that’s a rough number). So figure it has to fall on one of 31 days (that is, on your birthday) I’m assuming that any day is just as likely as another, though this isn’t true. There are 12 different years if I remember correctly, so that’s 31*12 =372 different animal/date combinations, and you’re looking for one. so there’s approximately a 1 in 372 chance that you’ll hit it on any given year. Let me point out that I don’t know just how far off this calc is, since I have a feeling that the CNY is more likely to fall in the center of the range I gave than at the ends.

Also - for people outside the chinese new year range, the chance of hitting this combo is 0.

The odds are 100% for you (since it has already proven true). For a random person to satisfy the conditions laid out in the OP, that person must have a birthday of Feb 7th in the year of the Rat. I calculate that as 1 in 4383 or 0.0228%.

I arrived at this number by multiplying the chance of having a birthday of Feb 7th (1 in 365.25) by the chance of being born in the year of the Rat (1 in 12).

HAPPY BIRTHDAY AUTO! Hope you get all liquored up and party like a biker.

Done.

ちょっと遅くて、こめんね！お誕生日おめでとう！（＾＿＾）
Hey! Happy Belated Birthday!