Calculation Methodology

Whole minutes are the source of truth

Clock times become integer minutes. Explicit calendar dates provide the day offset. We subtract unpaid break minutes and add paid minutes before formatting a two-place decimal display. Decimal-to-duration conversion rounds to the nearest whole minute.

Dates, midnight, and overlap

Dates are validated against the calendar, including leap days. An earlier end needs a later date. Equal start and end on the same date is rejected as ambiguous; a full day needs the next date. Multiple timecard periods cannot overlap, including an overnight period and the following morning.

These are wall-clock durations. Timezones, daylight-saving offsets, and leap seconds are not calculated. A clock-change shift needs verified offset-aware punches for actual elapsed time.

Workweeks

The week start is a user input. Biweekly timecards keep two seven-day totals. Overnight shifts display under their start date, and shifts crossing a workweek boundary must be split so each week gets the correct work and breaks.

Money and pay assumptions

Rates and monetary results are US dollars. Gross pay is minutes ÷ 60 × rate, rounded to cents. Overtime rounds regular and overtime components separately, then adds them. Thresholds and multipliers are explicit inputs. Salary conversion uses the entered weekly hours and paid weeks, not a hidden 2,080-hour constant.

For coverage and federal overtime guidance, see the U.S. Department of Labor's Fact Sheet 23. Actual rules can differ from the simplified inputs used here.

PTO ordering

The PTO estimate adds earned hours to the opening balance, applies the balance cap, subtracts usage, and then applies a carryover cap. This event order is visible in the tool. A policy that accrues and uses hours across several events needs separate calculations; the tool does not infer that timeline.

What is tested

Automated regression tests verify standard shifts, overnight dates, invalid dates, excessive breaks, decimal conversion accuracy, rounding, and PTO event ordering. Tests run on every build.

Corrections

Report reproducible errors through Contact. Include the tool, example inputs, expected result, and actual result. Material corrections update the reviewed date and relevant explanation.