How fast is "too" fast?

[Wooddog44]

I recently received, as a fifth anniv. present from my wife, a K series SS Submariner. I love it and am not "complaining" but merely looking for info from those more knowledgeable.
As a test I synched it with an internet time site yesterday at noon and today, at noon, it had gained approx. 8 seconds.
Is that a lot, a little, nominal, a problem?
I know that the stated Rolex parameters are -1 to +5 seconds and that it can be calibrated to a greater level of accuracy if I send it to Rolex but to be honest, now that I have it, don't want to part with it even for a couple of weeks.
It is under warranty for a year but is that amount of time gain even worth worrying about?