Purpose and scope
What this calendar builds
Generate alternating eight-hour Fridays and off Fridays around nine-hour workdays.
The 9/80 Work Schedule Calendar creates dated occurrences from Cycle begins, Weeks to preview, First Friday, and Daily start time; Trace Daily start time at cycle and month boundaries.
Instructions
How to use this calculator
Confirm Cycle begins and Weeks to preview as the 9/80 Work Schedule Calendar anchor, then confirm First Friday and Daily start time for the recurrence constraint.
- Confirm Cycle begins and Weeks to preview as the 9/80 Work Schedule Calendar anchor.
- Confirm First Friday and Daily start time for the recurrence constraint.
- Create the 9/80 Work Schedule Calendar output and trace its first Daily start time cycle.
- Evaluate the final 9/80 Work Schedule Calendar occurrence with Cycle begins and Weeks to preview.
Calculation
Method used
Monday through Thursday receive nine-hour blocks and Fridays alternate between eight hours and off.
The 9/80 Work Schedule Calendar advances Cycle begins, Weeks to preview, and First Friday between occurrences; trace Daily start time before applying any exclusion.
Calculation method last reviewed: June 21, 2026.
Visual audit
Reading the generated calendar
The 9/80 Work Schedule Calendar calendar creates entries from Cycle begins, Weeks to preview, First Friday, and Daily start time. Trace Daily start time across full cycles, weekends, and month boundaries.
Worked scenario
Example calculation
Evaluate the 9/80 Work Schedule Calendar example anchor with Cycle begins and Weeks to preview, then trace the Daily start time boundary direction.
Interpretation
Reviewing the generated schedule
The calendar exposes the repeating work pattern but does not establish which payroll week receives the extra hours.
Trace Daily start time on each 9/80 Work Schedule Calendar date; evaluate that Daily start time with the recurrence basis and constraint.
The 9/80 Work Schedule Calendar handles this calculation; the Compressed Workweek Planner can then build a repeating three-day or four-day workweek calendar from a weekly-hour target.
Practical use
Recommended workflow
Align the generated cycle with the employer's designated workweek and place holidays or leave over the baseline.
Boundaries
Important edge cases and limitations
The model does not determine the employer's workweek split, holiday handling, or overtime treatment.
Replace Daily start time through the 9/80 Work Schedule Calendar inputs; create the full constraint set instead of editing one date.
Input audit
Checklist for this calculation
- Trace the 9/80 Work Schedule Calendar anchor in Cycle begins and Weeks to preview.
- Evaluate the first occurrence with Daily start time.
- Trace Daily start time at weekends and month ends.
- Create the 9/80 Work Schedule Calendar again after a recurrence replace.
Questions
Frequently asked questions
Why does a 9/80 schedule need a defined workweek split?
The eight-hour Friday is commonly split between workweeks so each payroll week remains eighty hours across the cycle.
Which Daily start time occurrences in the 9/80 work schedule calendar deserve a boundary review?
Inspect the first and last 9/80 Work Schedule Calendar entries plus any date near a weekend, month end, or listed exclusion. Those positions expose most recurrence-boundary mistakes.
Which 9/80 work schedule calendar assumptions should travel with the output?
Save Cycle begins and Weeks to preview with the 9/80 Work Schedule Calendar output, then note First Friday and Daily start time and the calculation date so the result can be reproduced.