I have a Java app that runs on linux that has a lots of events and business logic that revolve around times and dates.
For testing, is it possible to tweak something into time going faster. Let’s say, make a whole computer-year finish in one hour wall time?
You can write a wrapper interface for your time/date calls. Have one real implementation that does real system calls, and a test implementation that can do whatever you want (run faster, slower, fake dates, etc).