What NOW does
NOW returns the current date and time. It is a volatile function, which means Excel recalculates it when the workbook recalculates.
That makes it useful for live timestamps, aging calculations, and dashboards that depend on the current moment.
Practical examples
Display the current date and time
=NOW()
Format the cell as date, time, or date-time depending on how much of the result you want to show.
Calculate elapsed hours
=(NOW()-A2)*24
If A2 holds an earlier date-time, this formula converts the elapsed time into hours.
Common mistakes and notes
NOW updates automatically
If you need a permanent timestamp, NOW is the wrong tool on its own. Use a keyboard shortcut or a controlled workflow instead.
Formatting changes what you see, not what you store
The result is one serial number. Formatting decides whether you see the date, the time, or both.
Volatile formulas can add overhead
Used sparingly, NOW is fine. Used across large models, it can make recalculation heavier than necessary.