Testing boundary timer

I use JUnit and the REST API to test my processes. What is the best way to test border timers with timeouts of a day or longer that are not practical to test this way.

Hello, I normally make the timers very short in testing (30 seconds, a minute). If it works at those times it will work for longer times. No way to test without waiting I’m afraid. Perhaps change the server clock? It seems a bit much.