Clock time versus duration
A clock reading identifies a point in the day; a duration measures elapsed time. From 09:10 to 17:40 is an 8 hour 30 minute span. The decimal equivalent is 8.50 hours because 30 minutes is half an hour—not 8.30.
Free Time Calculator & Hours Calculator
Total a full rota, calculate overnight shifts and unpaid breaks, or switch tools to add durations and find the time between two clocks.
Free to useSaved on your deviceInstant results
Useful guidance
One calculator for everyday time and shift totals
Use the work-hours view for a rota, or select a focused calculation above. Every result updates immediately and stays private on your device.
Day shift09:00–17:30, minus 30 minutes8 hr · 8.00 decimal
Night shift22:00–06:008 hr · next day
Three shifts8 hr + 8 hr + 7 hr 45 min23 hr 45 min
Which time calculation should you use?
Time problems look similar but need different arithmetic. Use Between times when you know two clock readings, Add or subtract when you already have durations, and Work hours when several shifts and unpaid breaks must be totalled. Keeping those inputs separate prevents the common mistake of treating minutes as hundredths of an hour.
Work records need break rules
For a paid-hours total, subtract only breaks that are genuinely unpaid under the relevant policy. Record each shift separately when start, finish or break lengths differ. That leaves a clear audit trail and makes overnight work easier to check.
Planning is not payroll approval
The calculator gives exact arithmetic from the values entered. Employers may apply rounding, minimum-callout, overtime or premium-pay rules afterwards. Compare the final total with the official timesheet or payroll policy before submitting it.
A worked example
| Shift | Clock span | Unpaid break | Counted time |
|---|---|---|---|
| Monday | 09:00–17:30 | 30 min | 8 hr |
| Tuesday night | 22:00–06:00 | 0 min | 8 hr |
| Wednesday | 08:15–16:45 | 45 min | 7 hr 45 min |
| Total | 23 hr 45 min · 23.75 hours | ||
The total is calculated in minutes first: 480 + 480 + 465 = 1,425 minutes. Dividing by 60 gives 23 full hours with 45 minutes left, or 23.75 decimal hours.
Police and public-sector rotas
Quick patterns
Load a common editable cycle in one click, then compare up to four people or teams and find meaningful time off together.
Choose the rota family—not just its name.Exact hours and sequences vary by force, service, station and local agreement. Confirm cycle day 1 and every time against the official rota.
Police response · control roomsPolice 6 on · 4 off2 earlies, 2 lates, 2 nights, then 4 rest daysUse this pattern →Police · fire · custody · NHS2 days · 2 nights · 4 offFour 12-hour shifts followed by 4 rest daysUse this pattern →Police response · mixed 12-hour and late dutiesPolice 16-week days · lates · nights112 days; cycle day 1 is the first of two 18:00–03:00 latesUse this pattern →Police control rooms2 days · 2 lates · 4 offTwo day shifts, two late shifts and 4 rest daysUse this pattern →Police · fire day crews · NHS4 days on · 4 offFour fixed day shifts followed by 4 rest daysUse this pattern →Wholetime fire watchesFire 2 days · 2 nights · 4 offTwo 10.5-hour days, two 13.5-hour nights, then 4 offUse this pattern →Ambulance and emergency cover2 days · 2 nights · 5 offFour 12-hour shifts followed by 5 rest daysUse this pattern →Fire nucleus · 24/7 public services2-2-3 day rotation2 on, 2 off, 3 on; then the inverse weekUse this pattern →Prisons · security · night teams7 nights · 7 offA 7-night block followed by a full week offUse this pattern →
Show 8 more quick patterns
Fire and ambulance
NHS and 24/7 services
NHS facilities · security · operations4 days · 4 off · 4 nights · 4 offFour days and four nights separated by 4-day breaksUse this pattern →Continuous operations4 days · 2 off · 4 nights · 2 offFour day shifts and four night shifts with 2-day breaksUse this pattern →24/7 operationsPanama 2-2-3 rotationAlternating 2-2-3 day and night sections over 28 daysUse this pattern →Continuous operationsDuPont 28-day rotationDay and night sections with a 7-day breakUse this pattern →
Other public sector
General patterns
Detailed rota guides
Check the cycle before you compare
Use these guides to understand overnight boundaries, cycle start dates and common setup mistakes.
Police 6 on, 4 off2 early shifts, 2 late shifts, 2 night shifts and 4 rest daysOpen guide →4 on, 4 off4 working days followed by 4 rest daysOpen guide →2 days, 2 nights, 4 off2 day shifts, 2 night shifts and 4 rest daysOpen guide →Panama 2-2-3Alternating 12-hour day and night sections across 28 daysOpen guide →DuPont rotationDays, nights and a seven-day break in a 28-day cycleOpen guide →