CST is 1h behind EDT (CDT stays 1h behind EDT when both use US daylight saving).

The time difference between Eastern Daylight Time (EDT) and Central Standard Time (CST) is 1 hour. CST is 1 hour behind EDT. Note that EDT is used during Daylight Saving Time (spring/summer), while CST is used during standard time (fall/winter).

EDT (Eastern Daylight Time, UTC-4:00) is used in the eastern United States during Daylight Saving Time, typically from March to November. CST (Central Standard Time, UTC-6:00) is used in the central United States during standard time, typically from November to March. When both regions observe DST, the difference becomes EDT (UTC-4:00) vs CDT (UTC-5:00), maintaining the 1-hour difference.

Here are some common time conversions:

9:00 AM EDT = 8:00 AM CST
12:00 PM (noon) EDT = 11:00 AM CST
3:00 PM EDT = 2:00 PM CST
6:00 PM EDT = 5:00 PM CST
9:00 PM EDT = 8:00 PM CST
12:00 AM (midnight) EDT = 11:00 PM CST (previous day)

EDT is used in eastern US states like New York, Florida, Georgia, and most of the East Coast during Daylight Saving Time. CST is used in central US states like Texas, Illinois, Missouri, and others during standard time. The 1-hour difference makes it easy to coordinate meetings and calls between these regions.