“A Matter of Time” is episode sixteen of season two of Stargate SG-1.
SG-10 are returning from a mission early but there is something wrong with the speed of transmission of their transponder code. They also fail to return through the stargate whilst it is open, so a MALP is sent through. The signal from the MALP also returns slowly.
SG-10 were visiting a binary system, but it’s one that now has one component that is a black hole. The presence of the black hole is slowing time down. Unfortunately, they can’t shut the stargate down, which means there’s an open portal to somewhere that’s a bit too close to a black hole leading to the SGC, and the time dilation effects are being transmitted through the gate. So other, rather more destructive, effects will probably be transmitted as well.
Now, I know black holes theoretically cause time dilation due to the gravity, but I think you’d have to be too close to the black hole to actually be able to live. I think if it was slowing down to that extent, the planet would already be ripped to pieces. Although they do seem to cover that, so at least it’s a factor that wasn’t completely overlooked.