Syntax
=EOMONTH(start_date, months)
start_date- The date to start from.
months- How many months to move: 0 for the same month, 1 for next month, -1 for last month.
EOMONTH function in Google Sheets
EOMONTH returns the last day of the month, a given number of months before or after a date. It's the standard way to find month-end due dates, the first day of a month and how many days a month has.
Practice EOMONTH
Task 1 of 4
Invoices are due on the last day of the month they were issued. Find the first invoice's due date in C2.
Tip: while typing a formula, click a cell or drag across cells to insert references. Press Enter to check, and Tab to accept a function suggestion.
EOMONTH examples
Each example below runs against this sample sheet. The results are calculated by the same engine as the practice grid.
| A | B | C | D | |
|---|---|---|---|---|
| 1 | Task | Start | Due | Holidays |
| 2 | Kickoff | 1/5/2026 | 1/9/2026 | 1/19/2026 |
| 3 | Design | 1/12/2026 | 2/13/2026 | 2/16/2026 |
| 4 | Build | 2/16/2026 | 4/30/2026 | 5/25/2026 |
| 5 | Launch | 5/4/2026 | 5/29/2026 |
| Formula | Result | What it shows |
|---|---|---|
=EOMONTH(B3, 0) | 1/31/2026 | The end of the month the Design task started. |
=EOMONTH(B3, 1) | 2/28/2026 | The end of the following month. |
=EOMONTH(B4, -1)+1 | 2/1/2026 | The first day of the Build start month. |
=DAY(EOMONTH(B3, 1)) | 28 | Days in February 2026. |
=EOMONTH(C3, 0)-C3 | 15 | Days from the Design due date to the end of its month. |
Tips and common mistakes
- EOMONTH(date, -1)+1 is the usual formula for "first of the month". It works for every month, including January.
- Format the result as a date, or it shows as a serial number.
Related functions
Learning step by step? EOMONTH is covered in Lesson 41: EDATE & EOMONTH of the free course.