Central Time Zone ( North America ) The Central Time Zone is a time zone in parts of Canada , the United States , Mexico , Central America , some Caribbean Islands , and part of the Eastern Pacific Ocean . Time in the zone is six hours behind Coordinated Universal Time ( Greenwich Mean Time - GMT ) . During daylight saving time ( DST ) , time in the zone is five hours behind GMT . It is not to be confused with the Central Time Zone in Australia , which covers South Australia and the Northern Territory . Regions using Central Time . Canada . The province of Manitoba is the only province or territory in Canada that observes Central Time in all areas . The following Canadian provinces and territories observe Central Time in the areas noted , while their other areas observe Eastern Time : Also , most of the province of Saskatchewan is on Central Standard Time year round . Because Saskatchewan is wholly within the Mountain Time Zone , it is effectively on DST year round . Major exceptions include Lloydminster , a town situated on the boundary between Alberta and Saskatchewan where the town charter stipulates that it shall observe Mountain Time and DST , putting the town on the same time as all of Alberta , including the major cities of Calgary and Edmonton . United States . The Central Time Zone is the second most populous after the Eastern Time Zone . Many states straddle time zone boundaries . Mexico . Most of Mexico — roughly the eastern three - fourths — lies in the Central Time Zone , with six of the northwestern states being exceptions : Baja California Norte , Baja California Sur , Chihuahua , Nayarit , Sinaloa , and Sonora . The states of Mexico that observe Central Time in their entireties : Mexico City , which is coterminous with the Federal District ( " Distrito Federal " ) , also uses Central Time . In Nayarit , however , only the municipality of Bahia de Banderas uses Central Time . Central Daylight Time . Daylight saving time ( DST ) is in effect in much of the Central time zone between mid - March and early November . The modified time is called Central Daylight Time ( CDT ) and is UTC−5 . In Canada , Saskatchewan does not observe a time change . One reason that Saskatchewan does not take part in a time change is that , geographically , the entire province is closer to the Mountain Time Zone ' s meridian . The province elected to move onto " permanent " daylight saving by being part of the Central Time Zone . The only exception is the region immediately surrounding the Saskatchewan side of the biprovincial city of Lloydminster , which has chosen to use Mountain Time with DST , synchronizing its clocks with those of Alberta . In those areas of the Canadian and American time zones that observe DST , beginning in 2007 , the local time changes at 02 : 00 local standard time to 03 : 00 local daylight time on the second Sunday in March and returns at 02 : 00 local daylight time to 01 : 00 local standard time on the first Sunday in November . Mexico decided not to go along with this change and observes their from the first Sunday in April to the last Sunday in October . In December 2009 , the Mexican Congress allowed ten border cities , eight of which are in states that observe Central Time , to adopt the U . S . daylight time schedule effective in 2010 .