Daylight Saving Time begins on Sunday, March 14, at 2:00 am
On Sunday, March 14, Daylight Saving Time (abbreviated DST) begins in the U.S. at 2:00 am in your local time zone.
The time change to Daylight Saving Time occurs on the the second Sunday in March, so when you go to bed on Saturday night, March 13, it's a good idea to set your clocks ahead by one hour (one hour later) before you go to bed so that you don't inadvertently 'lose' an hour of sleep on Saturday night, March 13, which is easily remembered by using the mnemonic "spring forward."
Conversly, in the fall, when Daylight Saving time ends and we revert back to Standard time for our time zone, we set our clocks back by one hour (one hour earlier) and can use the mnemonic "fall back." This change occurs on the first Sunday in November, this year on November 7, 2021, at 2:00 am. So on Saturday night, November 6, we will should set our clock back (earlier) by one hour because we will 'gain' an hour during the night due to the time change.
The beginning and ending of Daylight Saving Time is commonly used as the time to replace batteries in smoke alarms, to check if smoke alarms are in working order, and to set irrigation timers one hour earlier for those who have an automated irrigation system.
When testing a smoke alarm, it should sound when the "test" button is pressed. A good rule of thumb is to replace the alarm if it doesn't work properly when tested, or if the alarm is more than ten years old. Smoke alarms should be placed on every level of a home and near sleeping areas.