I've been meaning to post it on the day when InSight landed but just got around to it now.
When they broadcasted landing in real-time, it really wasn't in real-time because radio signals from Mars can take from 3 to 24 minutes to reach the Earth (depending on the distance between Mars and Earth) if I am not mistaken.
So what was the delay on the date InSight landed? Each time someone mentioned "real-time" I cringed a little bit because everything already happened some time ago and we were just only learning about it now.
Current delay for radio signals from the Mars InSight mission.
The delay at the time of the landing was 8.07 minutes (8 minutes 4+ seconds), as Mars was at the time at a relative distance from Earth of 0.9703 Au.
Current delay as at 8th December 2018, we're at a distance of 8.85 (8 minutes 51 seconds) light minutes or 1.064 Au.
Using WolframAlpha's tool here, you should be able to satisfy your curiosity without effort.
Times taken are at midnight on those dates and vary minimally throughout the day (eg. the delay on the day following launch at midnight was approx four seconds longer).
This does not take into account the time delay between the signal being sent to the satellite and it being decoded by your box and displayed by your tv or the time it may have taken to be distributed over the net if you watched it that way. I'm not able to determine if any Broadcast-Delay was deliberately introduced, which is a common practice and commonly is about 7 seconds.