System.currentTimeMillis(); If I change system time

Question

If I use System.currentTimeMillis() at 00:00 and I get X value.

Then I set the clock back one hour, and after one hour i call System.

Answer 1

In a nutshell, whenever you change system time, the value returned by System.currentTimeMillis() will change accordingly.

This is in contrast to System.nanoTime().