Show in planning under projects when an employee is on vacation

In our assembly planning, it is sometimes done in such a way that the employees who are on vacation are nevertheless planned for the corresponding construction site so that you can see in the project view which employees should actually be on the project and how long they may be on vacation. The information that they are on vacation is currently added manually after the printout. It would be nice that if an employee is planned for a construction site and is on vacation, it is also visible in the projects view that the employee has entered additional vacation. Possibly by streamlining, a different color or similar.