I usually go to the last home game of every season. It's frequently on a Sunday afternoon -- head-to-head with a Bears game. My recollection is that the Sunday afternoon game usually draws much better than the other games of the series (normally, it is Fan Appreciation Day).
I don't think holding Konerko Day on Friday or Saturday will increase attendance significantly. Whatever day of the week the Sox choose to honor Paulie, the game will likely draw between 17000 and 20,000 fans -- maybe fewer if the weather is bad. By late September, when their team is out of contention, the casual fan has turned the page on baseball season. The die-hards will attend regardless of the day of the week. Selfishly, I hope they honor Paulie on Sunday --I have tickets to that game, will attend to say good-bye and then watch the Bears highlights that night.