How to use the Days in Month Calculator
Enter a year and a month number from 1 for January to 12 for December. The tool returns 28, 29, 30 or 31.
Which months have 30 or 31 days
April, June, September and November have 30 days. February has 28, or 29 in a leap year. Every other month has 31. A quick trick is to count on your knuckles: each knuckle is a 31 day month and each gap between them is a shorter month.
How leap years work
A year is a leap year if it divides by 4, except for years ending in 00, which must also divide by 400. So 2024 and 2028 are leap years, 2000 was one, but 1900 was not. That rule keeps the calendar in line with the time Earth takes to go round the Sun.
How it works
Calendar month length, including leap-year February.
Examples
- With the default values
31 days
Limitations and assumptions
Uses the Gregorian calendar, which applies to all modern dates.
Frequently asked questions
How many days are in February 2028?
29, because 2028 is a leap year.
Which months have 31 days?
January, March, May, July, August, October and December.
How many days are in a year?
365 in a normal year and 366 in a leap year.