In Excel: use =DATEDIF(start_date, end_date, "d") — it returns the difference between two dates in the unit you ask for: "d" for days, "m" for whole months or "y" for whole years.
Syntax
Arguments
| Argument | Description | |
|---|---|---|
start_date | required | The earlier date — the start of the period. |
end_date | required | The later date — the end of the period; it must not be earlier than start_date. |
unit | required | The unit in quotes: "d" days, "m" whole months, "y" whole years, plus "ym", "yd" and "md" for the leftover part. |
Related functions
Breakdown: 0 years · 11 months · 30 days
Need it as an auditable file?
Ships inside the linked template — formula-driven, unlocked, audit-ready.
What this does
DATEDIF returns the gap between two dates measured in whole days, months or years, depending on a unit code you give in quotes. Beyond the basic "d", "m" and "y", three combination codes return only the remainder: "ym" the months ignoring whole years, "yd" the days ignoring whole years, and "md" the days ignoring whole months. It is most famous for age calculation — =DATEDIF(DOB, TODAY(), "y") gives a person's age in completed years. DATEDIF is an UNDOCUMENTED legacy function: it does not appear in Excel's function list and gives no autocomplete, but it works in every version. Notably the unit codes stay as the English letters "y", "m" and "d" even in German Excel. Keep the inputs visible and clearly labelled and the whole thing stays auditable — anyone who opens the file later, including you, can see at a glance exactly what feeds the result and change one assumption without hunting through the formula. For “excel workdays between two dates”, the reliable version is a short checking loop, not just the first command that appears to work. Run it on a deliberately small range first, watch how the affected cells change, and only then apply the same setup to the full sheet. When a formula is involved, keep the inputs labelled beside it, reference cells instead of typing values, and apply number formatting only after the result checks out. That is what makes a calculation you can defend to a CFO or an auditor useful in real work: repeatable, auditable, and not dependent on memory or luck.
A worked example
A start date 15/03/2020 sits in A2 and an end date 03/06/2026 in B2. =DATEDIF(A2, B2, "y") returns 6 (whole years), =DATEDIF(A2, B2, "m") returns 74 (whole months), and =DATEDIF(A2, B2, "d") returns 2271 (days). For an exact age string, combine units: =DATEDIF(A2, B2, "y") & " years, " & DATEDIF(A2, B2, "ym") & " months" returns "6 years, 2 months". For a live age, use TODAY() as the end date. DATEDIF is the simplest way to get a clean whole-number difference in years, months or days — the standard tool for ages, tenure and durations across every Excel version. If there is any chance you will reuse this, drop it into a small template tab right now: a labelled input area on the left and the formula beside it, checked once against the tool above. Next time the same question comes up, the answer is a single paste away instead of a rebuild from memory.
In Google Sheets
If you are in Google Sheets rather than Excel, the good news is that the formula shown here is identical and the workflow barely changes — menus sit across the top instead of in a ribbon, and a few function names differ slightly, but anything you build here moves across with little or no rework. The aim was to get you unstuck fast and leave you a little more capable than a copy-paste would. The answer is at the top, the tool proves it, and the detail above shows why it holds — so the next time a colleague asks, you can answer without reaching for search. If you take one thing from this page on “excel workdays between two dates”, make it the habit rather than the keystrokes: set the problem up with labelled inputs, reference those cells, and let Excel do the recomputing. Bookmark the page for the syntax, but do the example once in a blank sheet and check it against the tool above — five minutes of hands-on practice fixes the method in memory far better than re-reading, and it surfaces the small snags while they are still harmless. After that the technique is genuinely yours: faster than searching for it again, and reliable enough to drop into work that other people depend on.
Common mistakes
- Putting the dates in the wrong order — start_date must be the earlier date, or
DATEDIFreturns a#NUM!error. - Expecting "d" to count only working days —
DATEDIFcounts every calendar day; for weekdays useNETWORKDAYSinstead. - Translating the unit codes in German Excel — they stay as the English letters "y", "m" and "d"; only the argument separator changes to a semicolon.
Frequently asked questions
Why is DATEDIF not in the function list?
DATEDIF is an undocumented legacy function kept for Lotus 1-2-3 compatibility, so Excel offers no autocomplete or wizard for it. You must type it in full, but it calculates correctly in every version.
How do I calculate age with DATEDIF?
Use the "y" unit with TODAY() as the end date: =DATEDIF(DOB, TODAY(), "y") returns the age in completed years. Add "ym" and "md" parts if you want years, months and days.
Do the unit codes change in German Excel?
No. The unit codes stay as the English letters "y", "m" and "d" even in a German installation; the function name also stays DATEDIF, and only the argument separator becomes a semicolon: =DATEDIF(A2; B2; "y").