The Central Time Zone is a time zone in parts of Canada, the United States, Mexico, Central America, and a few Caribbean islands. It is one hour behind the Eastern Time Zone.
Daylight saving time is observed in most parts of that zone (20 states in the US, three provinces or territories in Canada, and several border municipalities in Mexico): Central Standard Time (CST) is observed from the first Sunday in November to the second Sunday in March. It is six hours behind Coordinated Universal Time (UTC) and designated internationally as UTC−6. From the second Sunday in March to the first Sunday in November the same areas observe daylight saving time (DST), creating the designation of Central Daylight Time (CDT), which is five hours behind UTC and known internationally as UTC−5.