What is the EOMONTH Function
The EOMONTH function returns the last day of the month that is a specified number of months before or after a starting date. It automatically knows how many days each month has, so you always get the correct month-end date.
Formula: =EOMONTH(start_date, months)
Practical Example 1
A2 contains 15-Jan-2026. Get the last day of the same month.
Type: =EOMONTH(A2, 0)
Result: 31-Jan-2026
Practical Example 2
Get the last day of the next month.
Type: =EOMONTH(A2, 1)
Result: 28-Feb-2026
Practical Example 3
Get the first day of the current month using EOMONTH.
Type: =EOMONTH(A2, -1) + 1
Result: 01-Jan-2026
Practical Example 4
Get the last day of the quarter.
Type: =EOMONTH(A2, 2)
Result: 31-Mar-2026
When to Use It
EOMONTH is used for month-end financial reports, invoice due date calculations, billing cycle endpoints, and any report where you need to know the last day of a specific month.