Last Day of the Month Calculator

Find the last calendar day of any month.

Any date in the month

Last day of the month

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What this calculator does

This calculator finds the last calendar day of the month containing any date you enter, correctly handling 28, 29, 30, and 31-day months.

Worked example

For any date in September 2026, the last day of the month isWednesday, September 30, 2026.

Common mistakes

Assuming every month has 30 or 31 days. February is the exception, with 28 or 29 days depending on whether it's a leap year.

Frequently asked questions

How does this handle February?+

It correctly returns February 28th in a common year and February 29th in a leap year.

What is this useful for?+

Common uses include finding rent or subscription due dates billed on the last day of the month, month-end accounting close dates, or deadlines described as "the end of the month."

How do you find the last day of a month online?+

Take the first day of the following month and subtract one day. This calculator does that instantly for any month and year, including correctly handling February in leap years.

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