In most of Mexico daylight saving time begins at 2:00 a.m. local time on the first Sunday in April. On the last Sunday in October areas on daylight saving time fall back to Standard Time at 2:00 a.m. local time. Central Standard Time (CST) becomes Central Daylight Time (CDT), and so forth. The state of Sonora does not observe daylight saving time. During daylight saving time turn your clocks ahead one hour. At the end of daylight saving time turn your clocks back one hour.