How it works.
DAYS calculates the total elapsed calendar days between an end date and start date.
Formula syntax.
Standard Excel Notation=DAYS(end_date, start_date)[like_this] are optional; all other arguments are required.Formula arguments.
Every parameter accepted by the DAYS function is detailed below.
The ending date in the interval.
Example value:B2The beginning date in the interval.
Example value:A2Simple example.
Step-by-Step ScenarioProject Timeline - Days Elapsed
Calculate the total calendar days between project kickoff and completion.
| Start Date | End Date | Days Elapsed |
|---|---|---|
| 2025-05-01 | 2025-05-31 | — |
| 2025-06-01 | 2025-06-15 | — |
=DAYS(B2, A2)Evaluates DAYS over the sample table cells, placing the verified output in cell C2.
Formula generator.
Full Generator WizardCustomize the argument fields below to generate a tailored DAYS formula ready to paste directly into your worksheet.
=DAYS()Expected result behavior.
Returns number 30 based on sample evaluation criteria and active cell references.
Best Practices
- Remember that end_date is listed first: =DAYS(end_date, start_date).
Common Mistakes
- If start_date is later than end_date, DAYS returns a negative number.
Platform & version compatibility.
Verified platform compatibility matrix based on actual spreadsheet calculation engine specifications.
Core standard function supported across all modern and legacy Microsoft Excel versions (365, 2021, 2019, 2016, 2013, 2010), as well as Excel for the Web and Mac.
100% compatible with Google Sheets. Uses identical argument order, data types, and standard calculation logic.
Frequently asked questions.
Technical Q&ACan I use DAYS across different worksheets in Excel?↓
Yes. You can reference cells located on other sheets by including the sheet name followed by an exclamation mark, for example: =DAYS(Sheet2!A2:A10). If the sheet name contains spaces, enclose it in single quotes: ='Q1 Report'!A2:A10.
What is the most common reason for errors in DAYS?↓
If start_date is later than end_date, DAYS returns a negative number.
Does DAYS work identically in Google Sheets?↓
Yes, DAYS is supported in both Microsoft Excel and Google Sheets with standard evaluation behavior.