Days in a Month Calculator
Find how many days are in any calendar month, accounting for leap years.
How to use this tool
- Enter year and month in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your days in month and the full breakdown beneath it.
Find how many days are in any calendar month, accounting for leap years.
How it works
This tool tells you exactly how many days are in a specific month of a specific year. Most months have a fixed length (January 31, April 30, etc.), but February varies between 28 and 29 days depending on whether the year is a leap year.
Enter a year and a month. The tool applies the Gregorian leap-year rule to determine whether February has 28 or 29 days, and returns the exact day count for every other month based on the standard calendar.
Knowing the length of a month is useful for payroll calculations (billing daily rates), scheduling (how many slots fit in a month), subscription management (prorating costs), and generating calendar views programmatically. It saves you from memorizing the "30 days hath September" rhyme or looking it up each time.
The result also displays the first and last day of the month as a convenient reference for setting date ranges in reports or database queries.
Worked example
How many days in February 2028?
- Select year: 2028
- Select month: February
- Click Calculate
- Read result: 29 days (2028 is a leap year)
29 days; February 1 to February 29, 2028
Common mistakes to avoid
- Assuming February always has 28 days and missing the leap day in calculations.
- Confusing September (30 days) with October (31 days) -- use the tool when precision matters.
- Entering only the month without the year, which makes it impossible to determine whether February has 28 or 29 days.
Key terms
- Leap year
- A year with 366 days, where February has 29 days instead of 28. It occurs in years divisible by 4, except century years unless also divisible by 400.
- Month length
- The total number of days in a calendar month, ranging from 28 to 31.
Frequently asked questions
- How does February work?
- February has 28 days in a common year and 29 days in a leap year. The calculator handles this automatically.
- Which months have 30 days?
- April, June, September, and November each have 30 days.