Eastern-to-Central is the reverse of the most-used US timezone conversion. New York-based companies with operations in Chicago, Houston, or Minneapolis subtract one hour to coordinate schedules.
Subtract 1 hour from Eastern to get Central. A 3 PM deadline in New York is 2 PM in Chicago. An 8 AM Eastern standup is 7 AM Central, which may be too early for some Central-based teammates.
The offset is permanently fixed at 1 hour. There is no point in the year where these two zones are the same time or two hours apart, since they both observe US DST identically.