The fastest way to change your iPhone's clock

Open Settings, tap General, then tap Date & Time. Toggle off Set Automatically if it is on. Tap the time display, use the plus and minus buttons to set the hours and minutes, then tap Done. Your clock updates when ready.

If you leave Set Automatically on, your iPhone pulls the time from your carrier or Wi-Fi network and changes it for you whenever you cross a time zone or when daylight saving time begins or ends. Most people leave it on for this reason. You only need to change it manually if you want a time that does not match your location, or if the automatic setting is giving you the wrong time.

Key Takeaways

  • Go to Settings > General > Date & Time to reach the clock controls.
  • Turn off Set Automatically to change the time by hand using the plus and minus buttons.
  • Your iPhone updates the time when ready once you tap Done.
  • Leaving Set Automatically on means your phone adjusts the time automatically when you travel or when daylight saving time changes.
  • If the automatic time is wrong, restart your phone or toggle airplane mode on and off before changing it manually.

When Set Automatically is giving you the wrong time

If your iPhone shows the correct time but Set Automatically keeps changing it to something wrong, the problem is usually a weak connection to your carrier or Wi-Fi network. Restart your phone first: hold the power button, slide to power off, wait 10 seconds, then power it back on. This forces your phone to reconnect and fetch the correct time from the network.

If restarting does not fix it, toggle airplane mode on for five seconds, then off again. This also resets your network connection. Once your phone reconnects, it should pull the correct time. If the wrong time persists after both steps, you can turn off Set Automatically and set the time by hand until your carrier or Wi-Fi connection stabilizes.

Changing the time zone without changing the actual time

Your iPhone has a separate setting for time zone, which controls how the clock displays the time but does not change what time it actually is. Go to Settings > General > Date & Time and look for Time Zone near the bottom. Tap it and search for your city or time zone name. Your display updates, but the actual time your phone uses stays the same.

This is useful if you travel but want to keep your phone on your home time zone temporarily, or if you live near a time zone border and want to display a different zone. The time zone setting only affects how the time appears on your screen and in your calendar — it does not change when alarms go off or when scheduled tasks run.

Why your iPhone's clock might be off by an hour

If your clock is exactly one hour ahead or behind, daylight saving time is usually the cause. In the United States, daylight saving time begins on the second Sunday in March (clocks spring forward one hour) and ends on the first Sunday in November (clocks fall back one hour). If Set Automatically is on, your iPhone should adjust on its own on those dates.

If your phone did not adjust automatically, restart it to force a network reconnection and time sync. If you are in a location that does not observe daylight saving time, or if you recently traveled, check your Time Zone setting to make sure it matches where you are now. Changing the time zone sometimes resets the daylight saving adjustment.

Using the 12-hour or 24-hour clock format

Your iPhone can display time in 12-hour format (with AM and PM) or 24-hour format (military time, where 1 PM shows as 13:00). This is a separate setting from the actual time. Go to Settings > General > Date & Time and look for 24-Hour Time. Toggle it on to use 24-hour format, or toggle it off to use 12-hour format. The change takes effect when ready across your entire phone.

This setting affects how the time appears in your clock app, lock screen, status bar, and calendar. It does not change when alarms sound or when reminders trigger — those still go off at the correct moment. Some people prefer 24-hour format because it removes any chance of confusing AM and PM.

Syncing your iPhone's clock with other devices

If you have a Mac, iPad, or Apple Watch, they all sync their time through iCloud when Set Automatically is on. They pull from the same network time source, so they should all show the same time. If one device is off by an hour or more, restart that device to force a time sync.

If you turn off Set Automatically on your iPhone and set the time manually, your other Apple devices will not automatically match it — they will keep their own automatic time. This can cause confusion if you use multiple devices. For this reason, most people leave Set Automatically on across all their devices.

Frequently Asked Questions

Can I set different times on different apps?

No. Your iPhone has one system clock, and every app reads from it. You cannot make one app show a different time than another. If you need to see multiple time zones at once, use the World Clock in the Clock app instead — it shows the current time in several cities without changing your phone's actual time.

What happens to my alarms if I change the time?

Alarms are set to go off at a specific time of day, not at a specific moment. If you change the time backward, an alarm set for 7 AM will go off when your clock reads 7 AM, even if that is sooner than you expected. If you change the time forward, the alarm will go off later. For this reason, avoid changing the time manually if you have alarms set for soon.

Why does my iPhone keep resetting the time I just set?

If Set Automatically is still on, your phone will override any manual time you set as soon as it reconnects to the network. Make sure you toggled off Set Automatically before changing the time. If it is off and the time still keeps changing, restart your phone and check that the toggle is actually off — sometimes it reverts after a restart.

Does changing the time affect my battery life?

No. Changing the time display does not use extra battery. Leaving Set Automatically on uses slightly more battery than turning it off because your phone checks the network for time updates, but the difference is negligible for most people.