Shift Calculator vs Time Card Calculator
Work time has a single-shift view and a weekly view. The shift calculator finds the missing clock time for one shift: given a start or end, the working duration, and any unpaid break, it returns the other end of the shift. The time card calculator totals a repeated weekly schedule: it converts daily start and end times into weekly regular and overtime hours with lunch deductions. One plans a shift on the clock; the other checks the week on the timesheet. The shift page links to the time card calculator for weekly totals, and the time card page links back to the shift calculator for single-shift planning.
What each calculator does
The Shift Calculator accepts a known start time or a known end time in 24-hour HH:MM format, a working duration, and break minutes. The duration unit matters: minutes mode uses the value directly, hours mode multiplies by 60, and the hours/min option treats the decimal part as a fraction of an hour — entering 8.5 means 8 hours 30 minutes, while 8.30 means 8 hours 18 minutes. Working minutes plus break minutes make the total clock span; the known time moves forward or backward by that span, and the result normalizes modulo 1,440 minutes, so overnight shifts display as ordinary clock times (22:00 + 8 hours + 30 minute break = 06:30) without a next-day date. The result panel shows shift times, effective time, total duration, and break percentage. The calculator rejects a break equal to or longer than the working duration.
The Time Card Calculator starts from the days worked (Monday through Sunday toggles), a single daily start and end time applied to every selected day, an optional lunch deduction, and a weekly overtime threshold defaulting to 40 hours. Daily clock hours are end minus start, with 24 hours added when the end is at or before the start so overnight shifts count correctly. If lunch is enabled, its minutes divided by 60 are subtracted from each day. The weekly overtime split is sequential: each day fills the remaining regular hours up to the threshold, and anything beyond counts as overtime. Output includes total hours, regular hours, overtime hours, hours per selected day, and a day-by-day breakdown.
Side-by-side comparison
| Feature | Shift Calculator | Time Card Calculator |
|---|---|---|
| Question | What are the start and end times of one shift? | What are the weekly regular and overtime totals? |
| Scope | One shift with working time and unpaid break | Repeated weekly days with lunch and overtime threshold |
| Inputs | Known start or end, duration, break minutes | Days worked, daily start/end, lunch, threshold |
| Core math | Start ± (working minutes + break minutes), mod 1,440 | End − start (plus 24 h overnight), minus lunch; threshold split per day |
| Overnight shifts | Yes — wraps to a normal 24-hour display | Yes — end ≤ start adds 24 hours |
| Overtime | Not split — scheduling math only | Regular up to threshold, remainder overtime |
| Best for | Planning a shift or handoff time | Checking a weekly timesheet or repeated schedule |
When to use which
Use the shift calculator when one shift is the unit of work: a nurse, warehouse crew, retail closer, or security post planning when a shift starts or ends. It keeps paid working time separate from the clock span — an 8 hour shift with a 30 minute unpaid meal period covers 8 hours 30 minutes on the clock — which is exactly the distinction the result panel makes visible. It does not total a week, split overtime, or store multiple days, and it works in wall-clock minutes only: a real overnight shift on a daylight-saving transition may contain one fewer or one more elapsed hour, so use an official payroll system when DST affects pay. The hours/min option’s decimal handling (8.5 vs 8.30) is worth reading before you use it.
Use the time card calculator when you have a repeated weekly pattern, such as Monday through Friday 09:00 to 17:00, and you want the week’s total with lunch deductions and overtime. Because every selected day uses the same start and end, irregular schedules need separate daily spans from the shift calculator or time duration calculator combined manually. The sequential threshold split matters: in the page’s example, six days of 7 paid hours produce 40 regular and 2 overtime hours, because Saturday fills the 5 remaining regular hours and the rest becomes overtime. Both calculators are arithmetic and planning aids — neither is a legal payroll record, and official payroll may apply rounding, paid breaks, daily overtime, state law, or union terms that the calculators do not model.
The two tools chain together naturally: plan each shift’s clean start and end times with the shift calculator, then enter them into the time card calculator for the weekly regular and overtime totals. For elapsed time with seconds, the time duration calculator is the third option in this family.
Where to start
- Shift Calculator — start and end time for one shift with unpaid breaks, on a 24-hour clock.
- Time Card Calculator — weekly regular and overtime totals from repeated daily schedules with lunch deductions.