This calculator adds a full 34-hour rest period to the time you go off duty, then rounds up to the next clean hour so you can see the earliest clock time your FMCSA 34-hour restart is complete.
34 Hour Reset Calculator
When a driver's 34-hour restart (FMCSA hours-of-service "reset") ends, from when off-duty time began.
What the 34-Hour Restart Calculator Covers
The 34-hour restart is an optional provision under the Federal Motor Carrier Safety Administration’s (FMCSA) hours-of-service rules that lets a commercial driver reset their weekly 60-hour/7-day or 70-hour/8-day on-duty limit by taking at least 34 consecutive hours off duty. This calculator covers 34-hour restart timing, FMCSA reset calculations, and figuring out the exact hour a driver becomes legal to start a new work week after a qualifying break.
Truck drivers, dispatchers, and fleet safety managers use this kind of calculation to plan pickup and delivery windows around a driver’s restart, avoiding both wasted downtime and hours-of-service violations.
How the Restart End Time Is Calculated
Formula
Restart Complete = Start Hour of Rest + Number of Full Days Needed to Reach 34 Hours
Where:
- Start Hour of Rest = the 24-hour clock time (0–23) the driver went off duty
- 34 = the minimum consecutive off-duty hours required for a valid restart
- The result rounds up to the next full day boundary since a partial day off duty still requires the full 34 hours to elapse before driving resumes
Worked Example
A driver goes off duty at 8:00 PM (20.0). Adding 34 hours to the start hour and rounding up to the next day boundary places the restart’s completion on day two at the corresponding clock hour — in this case, 6:00 AM two calendar days later, since 20 + 34 = 54 hours, which spans into the third day count from the original start.
The driver is not legally clear to begin a new work week under the restart provision until that full 34-hour block has elapsed.
Why This Matters for Compliance
Starting a new work week even a few minutes before the 34-hour restart is complete can create a logbook violation. Because the restart spans across calendar days and doesn’t align neatly with a single day’s clock, manually tracking the exact completion hour is a common source of error — this calculator removes that guesswork.
Frequently Asked Questions
Is the 34-hour restart mandatory?
No. It is an optional tool drivers can use to reset their 60/7 or 70/8 hour clocks. This is not legal advice — always confirm current FMCSA hours-of-service regulations and any exceptions that may apply to your operation.
Does the restart have to include two off-duty periods between certain hours?
Some restart provisions have included additional conditions in past rule versions (such as covering two periods between 1:00 a.m. and 5:00 a.m.). Because these requirements have changed over time, verify the current FMCSA rule in effect rather than relying solely on a fixed assumption.
Can I use this to plan a restart that starts mid-shift?
Enter the exact clock hour the driver goes off duty, even if that’s mid-afternoon or overnight — the calculator works from that starting point regardless of when in the day it falls.
What happens if I’m off duty for longer than 34 hours?
Any time off duty beyond the required 34 hours still satisfies the restart; the calculator shows the earliest possible completion time, not a maximum.
