According to Virginia regulations, people who drive with Uber are limited to driving a maximum of 13 total hours in any 24-hour period. Once you reach this limit, you won't be able to accept trips for 6 consecutive hours.
If you go offline at any point, that time will not be counted toward the 13-hour limit.
If your vehicle is stopped for more than 5 minutes while you're still online, anything after the first 5 minutes will not be counted toward the 13-hour limit.
The Driver app will notify you 2 hours and 1 hour before you reach the 13-hour driving limit, so you can plan when you want to go offline.
After 6 hours of being offline, you can come back online and continue driving on the app.