Testing a date program, over a long time

I wonder if it exist a way to test a real time programme on a short time.

I have a program which execute tasks 1 times in a year, or 1 times in a month, 1 time a day, many times in an hour, and so on. And all this tasks are mixed.

I can test it by changing the frequency (for exemple 1 times in a month becomes 1 times in a minute... I like to do many tests). But I think that some mistakes could be hidden by this process.

How are doing developpers ?

I thought about a Virtual Machine with a higher speed in the time system ?

I had quickly look the testing software, but I haven't find what I was looking for.