WorkTimeCheck performs time arithmetic from the values entered in each calculator. The general method is to convert clock times to minutes, apply the required addition or subtraction, then convert the result into hours and minutes or decimal hours.
Time duration formula
For a same-day interval, elapsed minutes = end time in minutes − start time in minutes. Example: 8:35 AM is 515 minutes after midnight and 5:20 PM is 1,040 minutes. 1,040 − 515 = 525 minutes, which equals 8 hours 45 minutes.
Overnight times
If an end time is earlier than its start time, the time-duration and work-hours logic treats the end as occurring on the following day. For example, 10:00 PM to 6:00 AM is calculated as 8 hours.
Unpaid breaks
Where a calculator accepts an unpaid break, net work time = elapsed shift minutes − entered break minutes. A 9-hour elapsed shift with a 30-minute unpaid break therefore produces 8 hours 30 minutes of work time.
Decimal hours
Decimal hours = total minutes ÷ 60. For example, 7 hours 45 minutes is 465 minutes; 465 ÷ 60 = 7.75 hours. Displayed decimal values are rounded to two decimal places.
Weekly and biweekly overtime estimate
Where displayed, the calculator separates time above 40 hours within each seven-day workweek and uses a 1.5× multiplier for the optional pay estimate. A biweekly card evaluates its two seven-day weeks separately rather than treating 80 hours as one overtime threshold.
This is an arithmetic estimate only. Overtime eligibility, applicable thresholds, exclusions and rates can differ by jurisdiction and circumstance.
Gross-pay estimate
Where an hourly rate is entered, estimated regular pay is regular decimal hours × hourly rate. Estimated overtime pay is overtime decimal hours × hourly rate × 1.5. The two estimates are then added for the displayed gross-pay estimate.
Dates, time zones and daylight saving time
WorkTimeCheck performs wall-clock arithmetic from the times you enter. Unless a calculator explicitly asks for a date or time zone, it does not model time-zone changes or daylight-saving transitions. For an interval that crosses a clock change, verify the actual elapsed time using the relevant date and time zone.
Validation
Representative cases include same-day durations, overnight shifts, break deductions, decimal conversions and separate-week overtime calculations. See Calculation Standards & Corrections for our checking and correction approach.