In general terms, the Law clearly states that all companies are required to keep a time record of each of their workers, and to properly record their working day, so that it is clear when it begins and ends, and also to keep this data for 4 years.
But outside of what is generic, there are very specific cases, such as that of an ambulance company that used the GPS data of the vehicles as a means of recording the working day. The union of this company denounced this practice, alleging that before starting to drive the ambulances, the workers had to go through the offices or do other administrative procedures, so their working day began before getting behind the wheel of the vehicle. Finally, the Supreme Court recognizes as certain the demand of the company's workers through a ruling.
All of this problem could be solved very simply with systems like Timenet, specifically with the marking module, since it allows you to configure as many marking devices and in as many locations as necessary, that is, each worker can have the marking point on their mobile phone, and thus can record all their working hours at the exact moment they start and end, even if their job requires constant movement.