CST to EST

Chicago and New York are the two halves of American finance. The New York Stock Exchange opens at 9:30 AM Eastern, which is 8:30 AM Central, so Chicago traders and analysts start their day at the same moment as Wall Street even though their clocks read an hour earlier. The same logic applies to anyone in Houston, Minneapolis or St. Louis working with East Coast clients: add one hour and you have New York time.

In summer the abbreviations change to CDT (UTC−5) and EDT (UTC−4), but the difference stays at one hour because both switch on the second Sunday of March and the first Sunday of November. A flight from O'Hare to LaGuardia takes about two hours, so a 7:00 AM departure lands around 10:00 AM Eastern after losing an hour on the clock.

The boundary does not follow state lines neatly. Most of Indiana is Eastern, but the northwest corner near Chicago (Gary, Hammond) and the southwest around Evansville use Central. Kentucky and Tennessee are split, with Nashville on Central and Knoxville on Eastern. The Florida Panhandle west of the Apalachicola River, including Pensacola, is Central, and four Michigan counties along the Wisconsin border are Central as well.

"CST" is also used for China Standard Time (UTC+8) and Cuba Standard Time, so in international email it is clearer to write "Central Time" or name the city. UltKit lists China separately. To compare Central Time with any other region, open the time zone converter.