The Excel NOW function returns the current date and time in a single number — the date as a serial day-count, the time as a decimal fraction riding behind it (0.5 = noon, 0.75 = 6 PM). Like TODAY it is volatile: it refreshes on every recalculation, which makes it perfect for "last refreshed" displays and useless for permanent timestamps — those want Ctrl+Shift+;.
Syntax
| Argument | Description | |
|---|---|---|
| (none) | — | NOW takes no arguments; the empty parentheses are mandatory. It reads the clock of the computer the workbook is open on. |
One number, two halves. Excel stores timestamps as a serial number: the integer part counts days since January 1, 1900, and the decimal is the fraction of the day elapsed. 3:00 PM on June 12, 2026 is 46185.625 — day 46,185 plus 15/24ths. Everything you do with NOW (subtracting, rounding, formatting) follows from that.
NOW is volatile, not live. It updates on every recalculation — any edit, F9, opening the file — but it does not tick by itself. A workbook nobody touches shows the time of the last recalc.
Date + time in one serial number
Format the same NOW() result different ways and the anatomy shows:
| A | B | |
|---|---|---|
| 1 | Formula | Result (June 12, 2026, 3:00 PM) |
| 2 | =NOW() | 06/12/2026 15:00 |
| 3 | =NOW() formatted as Number | 46185.625 |
| 4 | =INT(NOW()) | 46185 (the date part) |
| 5 | =NOW()-INT(NOW()) | 0.625 (the time: 15:00) |
Elapsed time is plain subtraction. If A2 holds a start timestamp:
Try it: watch the serial number tick
This panel recalculates every second — like pressing F9 over and over. Watch the decimal fraction crawl upward as the day burns down, then freeze a static copy the way Ctrl+Shift+; would.
Refresh stamps, deadlines, and elapsed time
The classic legitimate NOW: a "last refreshed" banner that updates whenever the model recalculates:
Time-sensitive logic compares full timestamps, not just dates:
Remember the units: a timestamp difference is in days. Multiply by 24 for hours, 1440 for minutes, 86400 for seconds — and format the result as a Number, or Excel may helpfully render your "3.5 hours" as a time of day.
Permanent timestamps: to record when something happened, don’t use NOW — it rewrites itself. Press Ctrl+Shift+; for a static time, or Ctrl+;, space, Ctrl+Shift+; for a static date and time in one cell.
Errors & common pitfalls
#NAME? — missing parentheses. =NOW isn’t a function call; Excel needs =NOW().
Pitfall: NOW as a permanent timestamp. Every NOW() in the workbook shows the time of the latest recalculation — your "order received" log silently rewrites itself all day. Stamp facts with Ctrl+Shift+; or Paste Special › Values.
Pitfall: =A2=TODAY() fails on timestamps. A NOW-style timestamp carries a time fraction, so it never equals the whole-number date from TODAY. Compare with =INT(A2)=TODAY().
Pitfall: elapsed hours show as a clock time. =(NOW()-A2)*24 in a cell formatted as a time displays nonsense like 6:00 AM instead of 30.0. Set the cell’s format to Number — the math is fine.
Practice workbook
Frequently asked questions
What's the difference between NOW and TODAY?
=NOW() returns date and time (46185.625 = 3 PM, June 12, 2026); =TODAY() returns the date alone (46185). Use TODAY for day-level math so stray time fractions don’t break equality tests.Does NOW update every second like a clock?
How do I insert the current time so it doesn't change?
How do I calculate hours between two timestamps?
Why does NOW() show a number like 46185.625?
Whose clock does NOW use?
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