Check the effect of a rounding interval
Choose a whole minute interval, such as 5, 10 or 15. The calculator rounds the minutes since midnight to the nearest multiple of that interval.
Exact halfway values round forward. The tool shows the arithmetic effect of a rule you choose; it does not decide which rounding practices apply to a workplace.
How to use this tool
- Enter the original clock time.
- Choose the rounding interval in minutes.
- Compare the rounded reading with the signed minute change.
Example
With a 15 minute interval, 09:07 rounds to 09:00 and 09:08 rounds to 09:15. The changes are 7 minutes back and 7 minutes forward.
Common questions
Can rounding cross midnight?
Yes. A late reading can round into the next day. The result notes that day change.