Hours of Rest Calculator (24h and 168h Rolling Checks)
This calculator helps vessel teams estimate rolling compliance by turning logged work periods into rolling rest checks for 24-hour and 168-hour windows. It supports exact date/time entries and a quick weekly day grid.
How to Use
- Add work periods manually with exact start/end date-time values, or fill the weekly grid.
- Click calculate to run rolling checks across all entered periods.
- Review the minimum rest found in 24h and 168h windows plus split-rest status.
- Use the result as an operational aid and confirm final interpretation with authorities.
Add Exact Work Period
Quick Weekly Day Grid (Optional)
| Day | Start | End |
|---|---|---|
| Mon | ||
| Tue | ||
| Wed | ||
| Thu | ||
| Fri | ||
| Sat | ||
| Sun |
Entered Work Periods
No work periods added yet.
Results appear here after calculation.
Frequently Asked Questions
What does this calculator validate?
It calculates rolling 24-hour and 168-hour rest totals and checks the common minimum thresholds of 10 hours in 24 hours and 77 hours in 7 days.
Can I use exact date and time entries?
Yes. You can add work periods with start and end date-time values and run the calculation instantly.
Can I also use a simple weekly day grid?
Yes. The day grid lets you add one daily work block per day using hour-minute times, based on a selected week start date.
How is split rest evaluated?
For each rolling 24-hour window, the tool evaluates whether rest can be represented in no more than two segments, with at least one segment of 6 hours and no more than 14 hours between consecutive rest segments.
Is this calculator a legal determination?
No. It is a planning and review aid. Operators should confirm interpretation and final compliance with their flag state and applicable rules.
Where can I read a broader compliance guide?
Use the STCW-F compliance guide for practical context, recordkeeping expectations, and inspection preparation.
See MarRest in Your Fleet
Request a free demo and walk through rest hour compliance with captains who built the system.
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