That effectively means the sun will come up an hour “later” on Sunday but will also mean the sun will stay up an hour “longer” in the evening.
Take note that most up-to-date computers and cell phones will automatically adjust their times. But to be safe, first rely on an accurately set clock.
Since 2007, daylight saving time has begun on the second Sunday in March and ended on the first Sunday in November for the vast majority of the United States that observes daylight time.