NOW - Calculate with the current date and time
Measure ticket age and time remaining using fractional days, while keeping recorded timestamps separate from recalculated values.
By the end, you can
- Interpret the time fraction of an Excel date/time.
- Convert elapsed days to hours.
- Avoid using a volatile formula as a permanent timestamp.
Before you start: Understand TODAY and calendar-day subtraction.
In this lesson
Date plus a time fraction
NOW returns the date and time at calculation. Its whole-number part represents the date and its fraction represents time within the day. At noon the fraction is 0.5. This makes a date/time difference measurable in days, hours, or minutes without treating the displayed time as ordinary text.
Syntax: no arguments
=NOW()NOW takes no arguments. The snapshot serial is 46303.4375: 10.5 hours divided by 24 is a 0.4375 time fraction.
- Use empty parentheses, just as with TODAY.
- Apply a date/time format when displaying the timestamp. Use Number formatting for a duration calculation.
Ticket age in hours
1.5| A | B | C | D | |
|---|---|---|---|---|
| 1 | Ticket | Opened date/time | Deadline date/time | Age hours |
| 2 | T101 | 08-Oct-2026 09:00 | 08-Oct-2026 11:00 | 1.5 |
| 3 | T102 | 07-Oct-2026 16:30 | 09-Oct-2026 16:30 | 18 |
=(NOW()-B2)*24From 09:00 to 10:30 is 1.5 hours. The serial difference is a fraction of one day, multiplied by 24.
- Keep the opened timestamp fixed in the source field.
- Subtract it from NOW to obtain elapsed days.
- Multiply by 24 for decimal hours, or by 1,440 for minutes.
- Check the overnight ticket: 07-Oct 16:30 to 08-Oct 10:30 is 18 hours, not a negative time.
Time left and minutes elapsed
=(C2-NOW())*24At 10:30, the 11:00 deadline is half an hour away.
=(NOW()-B2)*1440One day has 24×60=1,440 minutes, so the 1.5-hour age equals 90 minutes.
Use TODAY when a report should ignore time of day. A time-only format can hide the date and wrap an elapsed duration at 24 hours; choose an elapsed-time format such as [h]:mm or a numeric-hour calculation when appropriate.
Recalculation, clocks, and compatibility
- NOW is volatile but does not continually tick in an idle cell. It changes when the workbook recalculates.
- The workbook/environment's clock supplies the time basis. Subtracting timestamps from unrelated time zones without normalization can give misleading durations.
- The fractional day is numeric data; text formatted to look like a time is not necessarily a usable timestamp.
- NOW works in older/current Excel. Excel's 1900/1904 date-system setting matters when moving raw timestamp serials between workbooks.
Common mistakes and tips
The engine implements NOW, but no current Practice challenge matches these timestamp calculations.
Check your understanding
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