The driver's working hours are a set of regulations that define break periods and driving/travel time limits for vehicle drivers. The purpose of a driving time regulation law is to improve road safety and ensure good working conditions of drivers.
There may be not just a single regulation but many regulations that the driver has to abide by. For instance, one regulation may deal with working hours for all workers, and another regulation may deal with working hours for drivers of heavy vehicles only. Since drivers of heavy vehicles are also workers, both regulations apply to them.
We call a regulation that only affects drivers of heavy vehicles a driving time regulation because its primary goal is to limit the driving time of the driver.
We call a directive that affects all mobile workers working time directive because its primary goal is to limit the working time of workers.
If no driver object with a working hours preset is passed with the request, working hours will be unlimited.
Try it in the Drivers Working Hours code sample.