If you need to round a time to the nearest 15 minute interval, you can use the MROUND function, which rounds based on a supplied multiple. To round to the nearest 15 minutes, just supply “0:15” for the multiple.
How this formula works
The formula in C6 is:
MROUND rounds to nearest values based on a supplied multiple. When you supply “0:15” as the multiple, Excel internal converts 0:15 into 0.0104166666666667, which is the decimal value that represents 15 minutes.
You can also express 15 minutes in a formula with this formula:
The formula above divides 15 by 1440, which is the number of minutes in one day. So, to Excel, these formulas are identical:
Rounding to other time intervals
As you would expect, you can use the same formula to round to different time intervals.
To round to the nearest 30 minutes, or nearest 1 hour, use these formulas