You wouldn’t think that figuring out the end of the month would be a hassle, unless you regularly work through bill renewals, investment timelines, and financial projections or analyses in Excel. When you hover over a calendar or try to count the days in your head, especially in February, you’ll realize how disruptive this small step can be.
Fortunately, Excel already provides a built-in solution to this recurring annoyance. Once I add this function to my workbook, I no longer have to count days or double-check calendars for the exact month-end for me.
EOMONTH is the smarter way to calculate month-end dates in Excel
One formula to rule all month ends
EOMONTH, short for “End of Month,” is a built-in Excel function that returns the last day of a month relative to any date you give it. Because Excel stores dates as sequential serial numbers, EOMONTH technically returns a numeric value that corresponds to a specific calendar day. While that sounds technical, it simply means the result is a usable date that I can format, reference in other formulas, or place directly into a report. The function is available across virtually every version of Excel most people use, including Microsoft 365, Excel for the web, and desktop versions such as Microsoft Excel 2016 and Microsoft Excel 2019.
The syntax is simple:
=EOMONTH(start_date, months)
The first argument, start_date, is the date you want to count from. I prefer to enter it using any of the date functions in Excel, such as DATE(2024,1,1), or reference it from another cell to avoid parsing errors. The second argument, months, tells Excel how many months to move forward or backward. A positive number moves forward in time, while a negative number moves backward.
For example, the first formula below returns the serial number that maps to April 30, 2024 (45412), while the second returns the serial number for February 29, 2024 (45351), automatically accounting for the leap year:
=EOMONTH(DATE(2024,3,15), 1)
=EOMONTH(DATE(2024,3,15), -1)
Since Excel displays these results as serial numbers by default in the General format, you need to change the cell’s number format to a date format to see the calendar value we all know and understand. You can adjust the format either before or after entering the formula.
If you enter a decimal, such as 1.5, Excel truncates it to 1 rather than rounding up. To avoid confusion, always use whole numbers in the months argument.
The day you choose as the starting point does not affect the outcome. Whether the start_date falls on the 3rd, the 17th, or the 29th, the function consistently returns the final day of the target month. That reliability is why I trust this function when building spreadsheets that need to handle projections, billing cycles, and long-term financial planning without error.
Ways EOMONTH improves my Excel spreadsheets
Small function, big quality-of-life upgrade
If you look for places to use EOMONTH, you’ll find them almost everywhere. Most bills, utility payments, and subscription renewals fall on the last day of the month, and instead of hard-coding those dates and updating them manually every cycle, you can use EOMONTH to calculate them dynamically.
For example, if I want a payment due date to always reflect the last day of the current month, I use this formula:
=EOMONTH(TODAY(), 0)
I don’t even need to type in a specific date. Because the formula references TODAY(), the result updates automatically whenever I open the file, keeping my records current without any extra effort.
You can also combine EOMONTH with the IF function to make your spreadsheets more responsive. Imagine you have subscription statuses in column C and sign-up dates in column D. You can write this:
=IF(C3="Active", EOMONTH(D3, 1), "N/A")
With this formula, Excel only calculates the next billing date if the subscription is active. If C3 contains “Active,” EOMONTH takes the date in D3, advances it by one month, and returns the last day of that month. If the subscription is not active, the formula returns “N/A” instead.
In financial reporting, EOMONTH helps me define clear period boundaries. Whether I’m setting report cutoff dates, tracking expiration milestones, or defining the end of a fiscal quarter, the function ensures that my dates align precisely with the correct month-end. This becomes especially useful when I work with shifting monthly reporting periods, as I no longer have to manually adjust dates.
One example I rely on is dynamic headers for financial reports:
="Reporting Period Ends: " & TEXT(EOMONTH(A3, 0), "mmmm dd, yyyy")
This formula automatically generates a header that reads “Reporting Period Ends: [Last Day of Month],” based on the date in cell A3. I can reference a reporting month from another cell, such as E2, and place this formula at the top of my sheet to keep the reporting period clearly visible and always accurate.
These Excel spill formulas make dynamic dashboards ridiculously easy
One formula, endless automation.
EOMONTH is also useful for forecasting or calculating maturity dates for loans and investments. If a loan closes on March 10 and matures in 18 months, I want the maturity date to land on the last day of that 18th month. Instead of manually checking each calendar, I can rely on EOMONTH to handle the calculation. The same logic applies when I manage long-term project timelines. I no longer need to double-check whether it is a leap year before finalizing a February deadline, because EOMONTH automatically adjusts when February has 29 days instead of 28.
Let your spreadsheet do the counting
At first glance, EOMONTH looks almost too simple. At least, that is what I assumed until I realized how much mental energy I had been wasting by not using it. Whether I’m looking three months back with a -3 argument or projecting a year ahead with 12, the function keeps my spreadsheet dynamic and accurate without adding any extra work.
Once you’re comfortable with the basics, you’re all ready to nest EOMONTH inside other formulas and create date logic that practically thinks for itself.
