Excel Date to Number

What this does

Excel stores every date as a serial number: the count of days since January 1, 1900 (serial 1). Times are the fraction after the decimal point — 45443.5 is noon. The "date" you see is only a number format. That is why date math works (=B2-A2 is plain subtraction), why a date pasted into a General cell shows as a five-digit number, and why serial 60 is a famous oddity: it represents February 29, 1900, a day that never existed, kept for Lotus 1-2-3 compatibility. The same idea underpins a lot of everyday Excel work, so the few minutes spent getting it right here pay back across every sheet you build afterwards. Treat it as a pattern, not a one-off, and it stops being something you look up and starts being something you reach for. For “excel date to number”, 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 workflow that saves repeating the same clicks every week useful in real work: repeatable, auditable, and not dependent on memory or luck.

A worked example

A CSV import shows 45443 where a date belongs. Select the column, press Ctrl+1, choose Date — the cell now displays 31/05/2024. The stored value never changed; only the format did. To get a text date instead, =TEXT(A2,"yyyy-mm-dd") returns "2024-05-31". Serial numbers surface constantly — CSV exports, lookups returning 45443, dates pasted into General cells. Knowing they are formats, not values, turns a confusing five-digit number into a one-click fix. A practical tip before you scale it up: build it once on a small block of test data, confirm the number against the tool on this page, and only then point it at your real sheet. That one habit catches almost every mistake while it is still cheap to fix, long before a wrong figure reaches a report or a colleague.

In Google Sheets

Everything above works in Google Sheets too. Excel and Sheets share the formula syntax used here; only the surrounding menus are arranged differently. That portability is deliberate — learn it once and it follows you between the two tools and across Windows and Mac. Nothing on this page is behind a login: the tool runs entirely in your browser, the formula is shown in full with one-click copy, and the steps work the same on Windows and Mac. That is the whole promise here — the exact answer, a way to prove it on your own numbers, and just enough context to make it stick. If you take one thing from this page on “excel date to number”, 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

• Re-typing the dates by hand instead of changing the number format.
• Subtracting dates and formatting the result as a Date — a difference is a count of days; format it as Number.
• Mixing the 1900 system with files from old Mac Excel (1904 system), which shifts every date by 1462 days.
• Expecting serials for dates before 1900 — Excel cannot store them as dates.

Frequently asked questions