It's entirely up to you, as you can edit this value in hours in the User portal. You can even turn your computer off and on during this time. Seats are allocated to your machine and are not available to anyone else in your company. After the selected time has elapsed, the license automatically returns to the pool.
For new licenses created after May 1, 2022, the default is now only 1 hour. For all existing licenses, the default value remains 72 hours.