Forget the Adjacent Seed tool, you only need it for the previous generations.
How to handle the actual seconds: As said, you just have to remember the difference between the actual seconds and the second you have pressed - don't worry, it is constant, so you only need to do it once. The best way to get a consistent result is to use an external timer like EonTimer, or any timer that displays milliseconds.
Perform a calibration, take any second you want like 30. Try to hit it, then let the RNG Reporter search for the seed you have actually hit, take a look at the actual second. Tell us when you have it done.