PSA: Daylight Saving Time begins at 2am Sunday morning; your phone should adjust itself accordingly
In November 2010, when Daylight Saving Time ended, iOS failed to move its recurring alarm settings back an hour in certain locales, causing alarms to ring one hour later than scheduled. The following year, iPhone users had problems once again with the time change when clocks were supposed to move ahead by one hour. In 2012, some iPhone units moved the clock back an hour instead of ahead an hour with the start of Daylight Saving Time that year, and other units moved the clock forward four days early. The next year, some iOS users found the time on the calendar app to be one hour too fast about a week before the end of DST.
When you awake on Sunday morning, your current phone should have the right time posted. Of course, you might want to double check this by turning on your television, especially if you're using an iOS powered device.