Set cycle day one
Choose a real date that corresponds to the first day of each person's repeating pattern.
Compare Shift Patterns and Find Time Off Together
Overlay up to four repeating rotas, choose how much synchronized time off you need, and see every matching break across the dates you select.
2–4 patterns
Overnight aware
Saved on your device
Free to use
Loading calculator
Preparing the shift comparison…
Build each repeating cycle, then choose your minimum break
Add work and rest blocks
For a 2-day, 2-night, 4-off rota, add those three blocks in that order. The whole cycle then repeats.
Choose synchronized time
Set a minimum such as 48 hours. Only shared breaks at least that long are highlighted in green.
Shift-pattern comparison FAQ
What counts as synchronized time off?
Every selected pattern must be off work continuously for the same period. A result appears only when that shared window reaches the minimum number of hours or days you choose.
Can I compare more than two rotas?
Yes. Add a third or fourth pattern for a family, friendship group or team. The results then show only the windows when everyone is off together.
How are night shifts handled?
If a work block ends earlier than it starts, the calculator treats the finish as the following day. For example, 19:00–07:00 blocks time off until 07:00 the next morning.
Can I save or share a comparison?
Your current comparison is saved automatically in this browser. “Copy share link” creates a link containing the pattern settings so another person can open the same comparison; no account is required.
Does Time Calculator upload my rota?
No. The comparison runs in your browser. Your data stays on your device unless you deliberately copy and send a share link.
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 →