Go to the main Jam thread for the current event. The start and end times there will be stated in UTC. Subtract 5 hours (in the summer) or 6 hours (in the winter) to get the equivalent in Central Time. For
the upcoming event, that works out to 2023-08-31 7:00 AM to 2023-09-04 7:00 AM (CDT).
Alternatively, go to
the GMC Jam's unofficial site and use the countdown timer there, which is timezone-independent.