Spring Forward?

All morning I heard the people on the radio saying that this weekend is Spring Forward. I get it... we set our clocks an hour ahead, essentially losing an hour of sleep. What I don't get is that they kept saying that it's going to give us a longer afternoon. Won't it actually give us an hour LESS in the afternoon? I mean, today's 5pm will actually be 6pm once we spring forward, so wouldn't that just mean it will get darker sooner? I am confused!