Date & Time
NOW function: compare live timestamps and add hours to the current time
Understand how NOW stores the current date and time as a serial number + decimal fraction, how it differs from TODAY, and why it recalculates on edit.
How NOW combines integer date and fractional time
NOW() takes no arguments and returns a live serial number whose integer part is today's calendar date (matching TODAY()) and whose decimal part is the current time as a fraction of a 24-hour day (for example, .50 at 12:00 noon, .75 at 18:00).
Because 1.0 equals 24 hours, adding N / 24 to a timestamp moves forward by exactly N hours—such as NOW() + 6/24 for a 6-hour SLA window.
| Expression | Meaning | Behavior |
|---|---|---|
| =NOW() | Current date + current time | Decimal serial >= TODAY() |
| =INT(NOW()) | Date part stripped of time | Equals TODAY() |
| =NOW() - INT(NOW()) | Time-of-day fraction only | Always >= 0 and < 1 |
| =NOW() + 6/24 | 6 hours ahead of current time | Adds 0.25 days |
Add hours and test live SLA deadlines
Comparing NOW() against a deadline cell flags overdue items in real time whenever the workbook recalculates.
=IF(NOW() > A2, "Overdue", "Active")Volatile warning: NOW is not a static log stamp
NOW() is volatile: every time you recalculate or reopen the workbook, every =NOW() cell updates to the new clock time. Type a static date/time value—not =NOW()—when recording permanent audit timestamps.
=LET(t, NOW(), ROUND((t + 6/24) - t, 4))Try the example
Use the original values or change them to test your understanding.