Memphis, Tennessee is located in the Central Time Zone. During standard time, which runs from the first Sunday in November until the second Sunday in March, Central Time can be determined by subtracting six hours from Greenwich Mean Time. During Daylight Saving Time, which runs from the second Sunday in March until the first Sunday in November, Central Time can be determined by subtracting five hours from Greenwich Mean Time.
Tennessee, like most states, does observe Daylight Saving Time annually.
Most of Tennessee falls in the Central Time Zone, though the eastern part of the state falls in the Eastern Time Zone. If you were traveling east from Memphis on I-40, you would cross into the Eastern Time Zone in Roane County.