IANA Time Zones for Central Time: key details
The next change comes November 1, 2026, when US Central Time falls back from CDT to CST, at 2:00 AM local, clocks go back to 1:00 AM. For the 12,294,193 people in Mexico City, nothing changes; they're on permanent UTC−6. For developers, this means Chicago and Mexico City share the same offset from November through March. Come March 14, 2027, Chicago springs forward again, and the two cities diverge. Code for the transition, not the snapshot.