Days in Month Calculator
Choose a month and year to see how many days it holds — February's leap-year quirk included — and which weekday the month begins and ends on.
How it works
Every month has a fixed length except February, which is 28 days most years and 29 in a leap year. The calculator asks the calendar directly for the last day of your chosen month, so leap years are always right without you memorising the rule.
Once it knows the length, it looks up the weekday of the first and the last day. That's the bit that shifts year to year, and it's useful for laying out a planner, scheduling a recurring event, or working out how a month lines up.
Pick any year from history or the future — the leap-year logic follows the standard rule, so century years like 1900 and 2100 are handled correctly, not just the every-four-years shortcut.
Frequently asked questions
How does it decide leap years?
It reads the real calendar rather than guessing, so it follows the full rule: divisible by four is a leap year, except centuries, unless they divide by 400. That's why 2000 was a leap year but 1900 wasn't.
Why show the start and end weekdays?
Knowing a month starts on a Thursday and ends on a Saturday helps you sketch a calendar grid, count weekends, or plan around a month that begins mid-week.
Which months have 31 days?
January, March, May, July, August, October, and December each have 31. April, June, September, and November have 30, and February has 28 or 29.