At least in America, channels rebroadcast programs because of how many time zones the country covers. Not everyone will be around to watch a show at a specific time. If the channel re-airs it, people on the other side of the country get a chance to see it too. Discovery Channel does this too.
Use
http://www.tvguide.com/ to look up your local TV listings for your unique provider. It's surprisingly effective.
I found that Cobb Comcast is airing Balto five times this month alone!