Time correction simply accounts for the distance between your ears and the speakers. If you're trying to get good staging then you can set these to adjust the distance (I forget if alpine is ms or distance) If it's distance just put in the number of feet between your ears and the speakers...if it's time take the speed of sound (300m/s or so) and use this to adjust the deck. If you dont care, then just leave it off or set it to a minimal setting.
There you will find some selections in the center of the page to the left under "Alpine Support." Click "i-Personalize" and sign up. Everything after that is easy to follow with adjusting the settings on your Alpine HU's with the "i-Personalize" features such as time correction. I have done it with my 7998 and it made a noticable difference.