How nearest-increment rounding works
Divide minutes after midnight by the selected increment, round the quotient to the nearest whole number, and multiply back. Halfway points require a consistent tie-breaking rule documented by the payroll system.
With nearest 15-minute rounding, 9:07 is closer to 9:00 while 9:08 is closer to 9:15. A 6-minute increment represents one tenth of an hour, and a 5-minute increment represents one twelfth.
- 5-minute increments: 12 intervals per hour
- 6-minute increments: 10 intervals per hour
- 15-minute increments: 4 intervals per hour
- Nearest: selects the closest increment
- Up or down: always changes in one direction and can create systematic bias
Why neutral application matters
Time records should reflect all compensable work. A policy that repeatedly rounds employee time down, ignores pre-shift or post-shift work, or deducts time that was worked can create underpayment.
Preserve original punches and the rounded values. Review aggregate outcomes, exceptions, meal interruptions, and work performed outside scheduled hours. State rules and current court decisions may be more protective than a general federal summary.
Rounding versus decimal conversion
Rounding changes a timestamp or duration to a chosen increment. Decimal conversion simply expresses the same duration in base-10 hours. For example, 9:07 rounded to the nearest 15 minutes becomes 9:00, while seven minutes converted exactly is 0.1167 hour.
If your timekeeping system can capture actual minutes reliably, obtain current payroll or legal guidance before deciding whether any rounding policy is appropriate.