Different working hours for projects

Our employees record their times using the "time clock". The fixed breaks are defined and are also correctly taken into account by the program.

Now we have new construction sites in the city center for which a different working time should apply. The program ignores the entry of this different working time in the project. As the employees change construction sites in between, the working time cannot be stored in their master data.

According to 123 support, only the key "project time before personnel time" would be effective. But then the "time clock" no longer works.

Is there a way to adapt the program accordingly?