Syntax
=DAY(date)
date- The date to read.
DAY function in Google Sheets
DAY returns the day of the month of a date, from 1 to 31. Combined with EOMONTH it also tells you how many days a month has.
Practice DAY
Task 1 of 1
How many days are in the month of the first date? Answer in B2.
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.
DAY 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 |
|---|---|---|
=DAY(C2) | 9 | Kickoff is due on the 9th. |
=DAY(EOMONTH(B3, 0)) | 31 | Days in the month of the Design start (January has 31). |
=DAY(DATE(2028, 3, 0)) | 29 | Days in February 2028, a leap year. |
=IF(DAY(B2)<=15, "First half", "Second half") | First half | Which half of the month a date falls in. |
Tips and common mistakes
- For the day of the week (Monday, Tuesday…), use WEEKDAY or TEXT(date, "dddd") instead.
- DAY returns a plain number. Don't format the cell as a date.
Related functions
Learning step by step? DAY is covered in Lesson 39: Dates: DATE, YEAR, MONTH, DAY & WEEKDAY of the free course.