next week 8/7C

After 4 weeks stay at USA, I find a strange pattern to tell the forcast time schedule in TV. they always say something like the program will be on next Monday, 8/7c. (eight , seven centrol)

So what's the exect time of the forcast means?

try google it, there are two answers.

If the example is 8/7c. Then the program airs at 8 o'clock Eastern and 7 o'clock Central.

Another say the program airs at 8 o'clock you local time and 7 o'clock Central. which one is correct?

the united states mainland has four time zones:
Eastern(-5), Central(-6), Mountain(-7), Pacific(-8).