Help!

I was introduced to the eighth wonder of the world this Sunday...the NFL Red Zone channel.  I was over at a friend's place and watched it all Sunday, along with the regularily scheduled slate of games (I decided to take the week off of Direct TV).  The Red Zone channel, to me, almost makes Direct TV unneccessary.  I get to see cut-ins to all the games, during red zone and non red zone situations.  I can see all the teams, all the scoring plays, and all the action I may miss in the box score.  It even splits the screen if there is important action happening in two games at once.  Granted, I can't see all the games in their entirety, but I can't do that even with Direct TV without spending about ten grand to set up a war room.  Something tells me that doesn't fit into the wife's idea of our budget.

So, how do I get this channel at my house?  I think I'm supposed to have it, but I've never found it.  I'm a Comcast guy who has the sports package with the NFL Network and such.  Does this Red Zone channel just appear on Sundays?

Cheers,
TFAM