Days in Month
Find out how many days a given month has, leap-year rule included, so you know exactly how much time you have. Runs locally in your browser, GDPR-compliant.
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How to use this tool (video)
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Days in Month
The days-in-month calculator shows you how many days a given month has in a specific year. It automatically accounts for the leap year rule for February so you always get the correct day count.
How it works
The number of days per month follows a fixed pattern. January, March, May, July, August, October, and December each have 31 days. April, June, September, and November each have 30 days. February has 28 days in a normal year and 29 days in a leap year. The leap year rule states: a year is a leap year if divisible by 4, unless divisible by 100, unless divisible by 400. For a concrete example: February 2024 is a leap year, so it has 29 days. February 2023 is not a leap year and has only 28 days. April always has 30 days regardless of the year.
What the tool can and cannot do
The days-in-month calculator shows the correct number of days for every month of every year, including leap year adjustment. It automatically detects whether a year is a leap year and adjusts the February day count. The tool cannot add consecutive months together and does not calculate the difference between two dates. It does not display information about holidays or special calendar events. It is a pure day-count utility.
Why local processing in the browser
All calculations happen directly in your browser. Your date inputs are never sent to a server. There is no upload, no server log files, and no access by third parties. You need no account and no registration. After the page loads, the calculator works offline too because all resources are cached locally. There is no server that could be attacked and your data is not transmitted over the network.
Frequently asked questions
How many days does February have?
February has 28 days in a normal year and 29 days in a leap year. The leap year rule states: divisible by 4, but not by 100, unless divisible by 400.
Do I need to be online?
No, after the page has loaded once, the calculator works offline. The required resources are cached in the browser and a flaky connection will not interrupt you.
Are my data uploaded?
No, your date inputs are never sent to a server. Everything is processed locally in your browser with no upload and no third party access.
Which months have 30 and which have 31 days?
The months with 31 days are January, March, May, July, August, October, and December. The months with 30 days are April, June, September, and November. February is the special case with 28 or 29 days.
Can I also check the year 2000?
Yes, the year 2000 is divisible by 400 and therefore a leap year. February in the year 2000 had 29 days. The year 1900 is also checkable and was not a leap year.
Is the tool free to use?
Yes, the days-in-month calculator is a free tool that runs directly in your browser. There are no hidden costs or limitations.