Sonny, I don’t get what kind of different answer are you looking for. I already answered it at least 3 times, besides the fact that it was covered in the FAQ.
I can go further to technical details and explain why even if you set time to zero it still adds some random amount of time. I can go and explain every line of code, but I really don’t see a point for that. This is not a problem, this is not a sign of a problem. The problem is failing cron.