Fun little though about this: only on the centuries divisible by 400 is there a leap year, so it's a bit less or more than one nice day every 4 years on average over a person's life depending on which turn of the century they lived (ignoring how the length of their life affects how many leap years they experience).
A slightly easier way to think of this: leap years happen every 4 years, except that we skip one every 100 years (those that end in 00) unless it's divisible by 400. So we had a leap year in 2000 because it's divisible by 400, but 2100 will not be a leap year.