This is how the time for a TV program is given on American TV. The continental US has 4 time zones, and 2 television feeds for most networks. This would be an "east coast" feed and a "west coast" feed.
People in the Eastern time zone and the Central time zone watch the east coast feed. So a program would be on at 8 o'clock Eastern (which is 7 Central time). So 8/7Central. Or "8/7c" for short.
People in the Pacific time zone watch the west coast feed, which is delayed by 3 hours. So they also watch the program at 8 o'clock. (Though it is 8 Pacific, 11 Eastern)
(I have no idea what people in the Mountain time zone do, but apparently they deserve no special mention.)