Common Work Schedule Patterns Cheat Sheet
Use this work schedule patterns as a quick reference when checking work-time arithmetic. The table is designed to support manual verification and the calculators on this site; it does not interpret payroll rules or employment law.
| Pattern | Basic structure | Typical shift length | Cycle |
|---|---|---|---|
| 5×8 | 5 workdays | 8h | 7 days |
| 4×10 | 4 workdays | 10h | 7 days |
| 3×12 | 3 workdays | 12h | 7 days |
| 9/80 | 9 workdays | 8–9h | 14 days |
| 2-2-3 / Panama-style | 7 workdays | commonly 12h | 14 days |
| 4-on 4-off | 4 workdays, 4 off | varies | 8 days |
| DuPont-style | alternating blocks | commonly 12h | 28 days |
How to use the reference
Find the row that matches your minutes, schedule or shift example, then compare it with the values you entered in the related calculator. For overnight time, treat the end as occurring on the following date before subtracting the start. For decimal time, divide minutes by 60 rather than reading minutes as hundredths of an hour.
Why a reference table helps
A calculator is fast, but a table makes common values visible at a glance and helps you spot input mistakes. It is especially useful when reviewing recurring schedules, handwritten notes or spreadsheet entries where the same conversions appear repeatedly.
Use the matching calculator
For custom values, open the matching calculator and enter your own times or schedule details.
How the numbers are produced
Time conversion uses base-60 arithmetic. To convert minutes to decimal hours, divide the minutes by 60. To turn a decimal remainder back into minutes, multiply the decimal part by 60. Schedule totals use the same idea at a larger scale: calculate each work period, subtract only the break time you intentionally selected for the calculation, then add the resulting hours across the period.
Checks that catch most errors
- Confirm whether the end time belongs to the same date or the next date.
- Do not treat 30 minutes as 0.30 hours; it is 0.50 hours.
- When using monthly estimates, remember that an average month is not exactly four weeks.
- For rotating schedules, compare the full cycle instead of one convenient calendar week.
Reference tables are best used as a verification layer. If a value looks surprising, recompute it with the related calculator using the original start time, end time, break and schedule inputs.