The clock change happened on March 10, 2024, and will happen again on November 3, 2024

In the United States, clocks spring forward one hour at 2 a.m. on the second Sunday in March, and fall back one hour at 2 a.m. on the first Sunday in November. This year that meant clocks moved forward on March 10 and will move back on November 3. The change is called Daylight Saving Time, and it affects most of the country — though not all of it.

When clocks spring forward in March, you lose an hour of sleep that night. When they fall back in November, you gain an hour. The idea behind the change is to shift daylight hours to match when most people are awake, so evenings stay lighter longer during the months when the sun sets earlier.

Not every state observes Daylight Saving Time. Hawaii and most of Arizona do not change their clocks at all. Parts of Indiana, Michigan, and a few other states also stay on one time year-round. If you live in one of these places or travel to one, your devices may change automatically while you are there, which can cause confusion with meetings and alarms.

Key Takeaways

  • Clocks moved forward one hour on March 10, 2024, at 2 a.m., and will move back one hour on November 3, 2024, at 2 a.m.
  • The change happens on the second Sunday in March and the first Sunday in November every year in most U.S. states.
  • Hawaii, most of Arizona, and parts of a few other states do not observe Daylight Saving Time and keep the same time year-round.
  • Your phone and computer usually change automatically, but some older devices and appliances may need to be adjusted by hand.

Why the clock change happens at 2 a.m.

The change happens at 2 a.m. because it is the time when the fewest people are awake and traveling. If the change happened at noon or 6 p.m., it would disrupt commutes, meetings, and business operations. At 2 a.m., most people are asleep, so the disruption is minimal.

When clocks spring forward in March, 2 a.m. becomes 3 a.m. instantly. When they fall back in November, 2 a.m. becomes 1 a.m. This is why the hour between 1 a.m. and 2 a.m. happens twice on the November change night — clocks run through it twice.

Which devices change automatically and which do not

Smartphones, computers, and most modern devices change the time automatically through their operating system. Your iPhone, Android phone, Windows computer, and Mac all update without you doing anything, as long as they are connected to the internet or have the latest software.

Devices that may not change automatically include older alarm clocks, car clocks, microwave displays, oven clocks, and some smartwatch models. Check these devices the morning after the change and adjust them by hand if needed. Some car clocks update automatically if your vehicle is newer, but many do not.

If you have a device that did not change and you are not sure how to adjust it, look for a settings menu or a button labeled "time" or "clock." The manual or the manufacturer's website will show you the exact steps for that model.

What to do if the time change causes problems with your schedule

The most common problem is that alarms go off at the wrong time because they were set before the change. If you have an alarm set for 6 a.m. and you do not adjust it, it will go off one hour earlier (5 a.m.) after the spring change or one hour later (7 a.m.) after the fall change. Check all your alarms the day before the change and adjust them if needed.

If you have a meeting scheduled during the hour that changes, confirm the time with the other people involved. In March, the hour from 2 a.m. to 3 a.m. does not exist, so a meeting scheduled for 2:30 a.m. will not happen. In November, the hour from 1 a.m. to 2 a.m. happens twice, which can confuse calendar systems.

For most people, the bigger issue is sleep disruption. When clocks spring forward in March, you lose an hour of sleep that night. Going to bed and waking up at your normal times will help your body adjust faster than trying to sleep an extra hour.

States and regions that do not change their clocks

Hawaii does not observe Daylight Saving Time and stays on Hawaii-Aleutian Standard Time year-round. Most of Arizona does not change either and stays on Mountain Standard Time. The Navajo Nation, which spans parts of Arizona, New Mexico, and Utah, does observe Daylight Saving Time, so there are parts of Arizona that do change and parts that do not.

Parts of Indiana and Michigan also do not change their clocks. Some counties in these states stay on Eastern Standard Time year-round, while others follow the federal change. If you live near a state border or travel between regions, check which time zone applies to your location.

If you travel to one of these places, your phone will usually change automatically to the local time. This can cause confusion if you have meetings or calls scheduled back home. Before you travel, check what time zone the destination uses and adjust any important alarms or reminders.

How to prepare for the next clock change

The next clock change will happen on November 3, 2024, when clocks fall back one hour at 2 a.m. Mark this date on your calendar now so you do not forget. The change after that will be March 9, 2025, when clocks spring forward again.

A few days before the change, go through your devices and check which ones change automatically and which ones do not. Make a list of the devices you need to adjust by hand — your car clock, kitchen appliances, older alarm clocks, and any other devices with a time display. This takes only a few minutes and prevents you from being late or missing alarms.

If you have important meetings or calls scheduled around the time of the change, send a message to the other people involved to confirm the time. This is especially important if you are meeting with people in different states or countries, because not everyone observes Daylight Saving Time.

Frequently Asked Questions

Do I lose an hour of sleep when clocks spring forward?

Yes. When clocks move forward at 2 a.m., that hour is skipped, so you lose an hour of sleep that night if you go to bed and wake up at your normal times. Your body will adjust within a few days. Going to bed at your normal time and waking up at your normal time helps you adjust faster than trying to sleep extra.

What time is it during the hour that does not exist in March?

When clocks spring forward in March, the time jumps from 1:59 a.m. to 3:00 a.m. The hour from 2 a.m. to 3 a.m. does not exist that night. If a meeting or event is scheduled for 2:30 a.m., it will not happen as scheduled — the time will skip over it.

Will my phone change automatically?

Yes, if your phone is a smartphone (iPhone or Android) and it is connected to the internet or has the latest software. Your phone will change automatically at 2 a.m. on the change date. Older devices like basic alarm clocks, car clocks, and some appliances will not change automatically and need to be adjusted by hand.

What happens to my calendar and scheduled meetings?

Most calendar apps (Google Calendar, Outlook, Apple Calendar) update automatically and adjust the times of your meetings. However, if you have a meeting scheduled for 2 a.m. in March or between 1 a.m. and 2 a.m. in November, there may be confusion. Check your calendar the day before the change and confirm important meetings with the other people involved.

Why do we still have Daylight Saving Time if most people do not like it?

Daylight Saving Time is a federal law, but states can choose not to observe it. Hawaii and Arizona do not change their clocks. Some states have tried to make Daylight Saving Time permanent year-round, but federal law currently requires the change to happen twice a year in states that observe it.