If I ranked my top 5 all time sci-fi shows, this one would come in at #5 (Dr. Who, Stargate SG-1, Farscape, and The Dead Zone are 1-4).
Excellent cast and lots of action every episode, as Lt. Frank Parker was sent back in time exactly 7 days to prevent catastrophic events from occurring. Like Quantum Leap and Voyagers before it, these "fixing historical errors" shows are always intriguing. While those two earlier shows would go back years in time to fix history, here they could only go back a week to fix recent bad events. Previously unseen for years, it was finally released on DVD in the US this January.
It ran on the smaller UPN network in the US and didn't air in syndication afterward, or come out on dvd until this year. UPN only lasted about 10 years, but had a few quality shows like this one, The Sentinel, and Star Trek Enterprise. They also aired a few other obscure but good sci-fi shows that only lasted one season like Nowhere Man, Level 9, and Deadly Games.