Days in Each Month

This page shows how many days every month has, and lets you check any specific month and year — handy because February is the one month whose length changes, between 28 and 29 days, depending on the leap year.

Eleven of the twelve months have a fixed length that never changes. Seven months have 31 days — January, March, May, July, August, October, and December — and four have 30 days — April, June, September, and November. Only February varies: it has 28 days in a common year and 29 days in a leap year, when the extra day (29 February) is added to keep the calendar aligned with the Earth's orbit around the Sun.

Two old memory tricks make the pattern easy to recall. The first is the rhyme: Thirty days hath September, April, June, and November; all the rest have thirty-one, except February alone, which has twenty-eight days clear, and twenty-nine in each leap year. The second is the knuckle method: make a fist and count across the knuckles and the dips between them, starting with January on the first knuckle. Months that land on a knuckle have 31 days; months in a dip have 30 — with February the sole exception at 28 or 29.

To use the tool, pick a month and — if you are checking February — enter the year, then press Show days in the month. The result names that month's length and, for February, tells you whether the year is a leap year. The leap-year rule is applied automatically, so February is always right: a year is a leap year when it is divisible by 4, except century years, which must also be divisible by 400 (so 2000 was a leap year, but 1900 was not).

Knowing a month's length matters for counting days to a deadline, working out billing or payroll periods, and planning schedules. To count the exact days between two dates, use the days between dates calculator; to confirm whether a year is a leap year, use the leap year calculator; and to see a full year laid out month by month, open the calendar pages.

Every month has a fixed number of days except February. Seven months have 31 days and four have 30; February has 28 days, or 29 when the year is a leap year — divisible by 4, but for century years only when also divisible by 400.