Days in Month Calculator
Pick a month from the dropdown and type a year to see exactly how many days that month holds. February is handled with the full Gregorian leap-year rule, so a century year like 1900 gets 28 days while 2000 gets 29. The result also names the weekday the 1st falls on and whether the year is a leap year, and you can copy the summary in one click.
How to find the number of days in a month
- Choose the month from the Month dropdown.
- Type the full year into the Year field, for example 2026.
- Read the large day count shown in the result panel.
- Check the line that names the weekday the 1st starts on.
- See whether it flags the year as a leap year, then use Copy to grab the summary.
Examples
February in a leap year
February 2024
29 days, leap year, starts on a Thursday.
February in a common year
February 2023
28 days, not a leap year, starts on a Wednesday.
A thirty-day month
April 2026
30 days, not a leap year, starts on a Wednesday.
Frequently asked questions
How many days are in February?
February has 28 days in a common year and 29 in a leap year. February 2024 has 29 days, while February 2023 and February 2025 each have 28.
Which months have 31 days and which have 30?
January, March, May, July, August, October and December have 31 days. April, June, September and November have 30. February is the only variable month.
How does the tool decide if a year is a leap year?
It applies the Gregorian rule: a year is a leap year if divisible by 4, except century years, which must also be divisible by 400. So 2000 is a leap year, but 1900 and 2100 are not.
How is the starting weekday worked out?
The tool uses Sakamoto's algorithm, a compact and well tested method for the day of week. It returns the exact weekday of the 1st for any year on the Gregorian calendar.
Can I enter years before 1900 or far in the future?
Yes. The year field accepts any whole number, and the leap-year and weekday maths hold across all of them. Bear in mind that dates before 1582 predate the Gregorian calendar in most countries, so historical records may differ.
Why does February 1900 show 28 days when 1900 is divisible by 4?
Because the century exception applies. A year divisible by 100 is only a leap year if it is also divisible by 400, and 1900 is not, so it keeps 28 days.
What does the Copy button put on my clipboard?
It copies a one-line summary such as February 2024 has 29 days. It starts on a Thursday (leap year). That makes it easy to paste into notes, a spreadsheet or a message.
Does the tool change with my time zone or today's date?
No. The result depends only on the month and year you choose, not on the clock. The form simply starts on the current month and year for convenience.
Is anything sent to a server?
No. The calculation runs entirely in your browser, so the month and year you enter stay on your device.
Learn more
- Leap year rules and why February changes length
How the divisible-by-4, 100 and 400 rules decide February's length, why century years are special, and where the extra day comes from.
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