Daylight saving time changes happen twice a year in the United States

In most of the U.S., clocks move forward one hour on the second Sunday in March and back one hour on the first Sunday in November. The spring change is called "springing forward" — you lose an hour of sleep. The fall change is called "falling back" — you gain an hour. These dates are set by federal law, so they are the same across every state that observes daylight saving time.

Not every state follows this schedule. Hawaii and most of Arizona do not observe daylight saving time at all, so their clocks never change. Some U.S. territories like Puerto Rico and Guam also stay on standard time year-round. If you live in one of these places, you do not need to change anything.

The exact moment the change happens is 2 a.m. local time. When clocks spring forward in March, 2 a.m. becomes 3 a.m. When clocks fall back in November, 2 a.m. becomes 1 a.m. Most people are asleep when this happens, but your devices handle it automatically if they are set up correctly.

Key Takeaways

  • Daylight saving time changes on the second Sunday in March (spring forward) and the first Sunday in November (fall back) in most U.S. states.
  • The change happens at 2 a.m. local time, and most phones, computers, and smart devices update automatically if connected to the internet.
  • Hawaii, Arizona, and some U.S. territories do not observe daylight saving time and their clocks never change.
  • Older devices, appliances, and systems that are not connected to the internet may not update on their own and require manual adjustment.

How your phone and computer handle the time change automatically

Your smartphone, laptop, and tablet update the time automatically if they are connected to the internet and have the correct time zone set. When the change happens, your device receives a signal from a time server that tells it to shift the clock forward or backward. This happens in the background without you doing anything.

To make sure your device updates correctly, check that automatic time and date settings are turned on. On an iPhone, go to Settings > General > Date & Time and turn on "Set Automatically." On an Android phone, go to Settings > System > Date & Time and turn on "Automatic date & time" and "Automatic time zone." On a Windows computer, go to Settings > Time & Language > Date & Time and turn on "Set time automatically." On a Mac, go to System Settings > General > Date & Time and make sure "Set date and time automatically" is checked.

If your device is not connected to the internet or these settings are turned off, the time will not change automatically and you will need to adjust it by hand. Devices that are offline for long periods may also fall out of sync and need a manual correction.

Devices and appliances that do not update automatically

Older devices, car clocks, and appliances that are not connected to the internet will not change on their own. This includes microwave ovens, wall clocks, alarm clocks that are not smart devices, car dashboards, and some fitness trackers. You will need to change these by hand on the day of the time change or shortly after.

Smart home devices like smart speakers and smart thermostats usually update automatically if they are connected to your home Wi-Fi and have the correct time zone set during setup. However, if you have an older smart device or one that lost its internet connection, you may need to manually adjust it through the device's app or settings menu.

Backup systems, security systems, and older computer equipment in offices or homes may also require manual updates. If you have devices that are critical to your daily routine — like a medication reminder or a work alarm — check them the day before the time change to see if they updated automatically or if you need to adjust them yourself.

What to do if your device did not change the time

If you notice your device is showing the wrong time after the change, the first step is to check whether automatic time settings are turned on. Follow the steps listed above for your device type. If automatic settings are already on and the time is still wrong, restart your device — turn it off completely and turn it back on. This often forces the device to sync with the correct time.

If restarting does not work, check that your device is connected to the internet. A device that is offline cannot receive the time update signal. Connect it to Wi-Fi or cellular data, wait a few minutes, and check the time again. If it is still wrong after that, you can manually set the time through your device's settings menu.

For devices that do not connect to the internet at all, you will need to change the time manually using the device's buttons or menu. Check the device's instruction manual or manufacturer's website for the exact steps, as the process varies widely depending on the type of device.

Planning ahead to avoid confusion on time change day

The best way to handle the time change is to prepare a day or two before it happens. Check the devices you use most often — your phone, computer, car, and any smart home devices — to confirm they have automatic time settings turned on and are connected to the internet. Make a list of devices that do not update automatically, like wall clocks, microwave ovens, and alarm clocks, so you remember to change them.

On the day of the change, set a reminder on your phone for the morning after the change to check a few key devices and confirm they updated correctly. This is especially important if you have devices that control important routines, like a medication reminder or a work alarm. If you find one that did not update, you can fix it right away instead of discovering the problem later.

If you travel across time zones during daylight saving time, your phone will usually update automatically when you arrive, but it is worth checking. Some older phones or devices may not recognize the new time zone right away, so manually confirm the time when you land.

Why the time change happens and which states skip it

Daylight saving time was created to make better use of daylight hours during the warmer months. The idea is that by shifting an hour of daylight from morning to evening, people use less electricity for lighting. The practice started during World War I and has been used on and off in the United States ever since. The current schedule — second Sunday in March and first Sunday in November — has been in place since 2007.

Hawaii stopped observing daylight saving time in 1967 and has not changed since. Arizona stopped in 1968, though the Navajo Nation within Arizona does observe it. Most of the U.S. Virgin Islands, Guam, American Samoa, and Puerto Rico also do not observe daylight saving time. If you move to or from one of these places, you will need to adjust to a permanent one-hour difference.

Some states have tried to make daylight saving time permanent year-round, but federal law currently does not allow this. States are allowed to stay on standard time permanently, but not to stay on daylight saving time permanently. This means the twice-yearly change is likely to continue in most of the U.S. for the foreseeable future.

Frequently Asked Questions

Do I need to change my phone's time manually?

No, if your phone is connected to the internet and automatic time settings are turned on, it will update by itself. Check your phone's settings the day before the change to confirm automatic time is enabled. If it is, you do not need to do anything.

What time should I change my clocks if I do it manually?

Change your clocks at 2 a.m. on the day of the change. In March, move them forward one hour (2 a.m. becomes 3 a.m.). In November, move them back one hour (2 a.m. becomes 1 a.m.). Most people do this the night before or the morning after, whenever is convenient.

Will my car's clock update automatically?

Most modern cars with connected infotainment systems will update automatically. Older cars with mechanical or basic digital clocks will not. Check your car's manual or try the settings menu to see if automatic time is available. If not, you will need to adjust it manually.

What happens if I forget to change my clocks?

Your devices that update automatically will be correct. Any device you change manually will be off by one hour until you fix it. This usually causes minor confusion with alarms or schedules, but you can correct it anytime by adjusting the clock forward or backward.

Does daylight saving time happen on the same day everywhere in the world?

No. The United States changes on the second Sunday in March and first Sunday in November. Europe changes on the last Sunday of March and October. Other countries have different schedules or do not observe daylight saving time at all. If you work with people in other countries, check their local time change dates.