Shortly after it was announced that the Sabres will be facing the Flyers in the opening round of the Stanley Cup Playoffs, a friend of mine (Richard Stan) did a quick dig.  Here's what he came up with...

The Wells Fargo Center in Philadelphia currently has the 76'ers versus the Detroit Pistons scheduled on Wednesday, April 13th.  I highly doubt the NBA contest will be moved, so I think it's safe to predict as Rich suggests the series will open in Philadelphia in Thursday, April 14th.

Also, the Philadelphia Soul of the Arena League play Friday, April 15th in the Wells Fargo Center.  I'm sure they could be paid off to move their game, but I doubt the NHL would want back to back playoff games within a series.  So it looks like game #2 would be either Saturday or Sunday.  I'll predict on a hunch that it'll be an afternoon game.