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 hour and minute, then tap Done. Your clock updates when ready.

If you leave Set Automatically turned 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 shifts. Most people keep this on. You only need to change it manually if you want a time that does not match your actual location, or if your phone is showing the wrong time despite automatic updates being on.

Key Takeaways

  • Manual time changes happen in Settings > General > Date & Time after you turn off Set Automatically.
  • Leaving Set Automatically on means your iPhone updates the time without your action whenever you travel or when daylight saving time changes.
  • If your clock shows the wrong time even with Set Automatically on, try turning it off and back on, or restart your phone.
  • The time zone setting is separate from the clock time — changing one does not automatically change the other.

When to turn off automatic time updates

You might turn off Set Automatically if you want your phone to show a time that does not match your location. Some people do this when traveling for work but wanting to stay on their home time zone, or when testing an app that depends on a specific time.

Another reason is troubleshooting. If your iPhone keeps showing the wrong time even though Set Automatically is on, turning it off and setting the time manually can help you figure out whether the problem is with automatic updates or with your phone's clock itself. After you set it manually and confirm the time is correct, turn Set Automatically back on to see if it stays correct.

Changing your time zone separately from the clock

Your iPhone has two separate settings: the time zone and the actual time. If you change your time zone in Settings > General > Date & Time, your phone automatically adjusts the clock to match — but only if Set Automatically is on.

If Set Automatically is off, changing your time zone does nothing to the clock display. You have to adjust the time manually. This matters if you travel: your phone can show the correct local time in your new location only if you either turn Set Automatically on, or manually change both the time zone and the clock time yourself.

What to do if your iPhone clock is wrong

First, check whether Set Automatically is on. Go to Settings > General > Date & Time and look at the toggle. If it is on and your time is still wrong, turn it off, wait a few seconds, then turn it back on. This forces your phone to fetch the time from your network again.

If that does not work, restart your iPhone. Hold down the power button and volume button together until the power-off slider appears, slide to power off, wait 10 seconds, then hold the power button again until the Apple logo shows. After restart, check whether Set Automatically is still on and whether the time is now correct.

If your clock is still wrong after restart, your phone may have lost connection to the network. Make sure you are connected to Wi-Fi or cellular service. If you are connected and the time is still wrong, the issue may be with your carrier or network, not your phone — in that case, contact your carrier to report the problem.

How automatic time updates work across time zones

When Set Automatically is on, your iPhone gets the time from your cellular carrier or from the Wi-Fi network you are connected to. When you travel and cross into a new time zone, your phone detects the change and updates both your time zone setting and your clock automatically. This usually happens within a minute of connecting to a network in the new location.

The phone does not use GPS to figure out where you are — it uses the network. If you travel but stay on airplane mode or do not connect to any network, your phone will not know you have moved and will not change the time zone or clock. Once you connect to Wi-Fi or turn on cellular service, the update happens on its own.

Changing the time format from 12-hour to 24-hour

Your iPhone can display time in 12-hour format (with AM and PM) or 24-hour format (military time). This is a separate setting from the actual clock time. Go to Settings > General > Date & Time and look for 24-Hour Time. Toggle it on to switch to 24-hour format, or toggle it off to use 12-hour format.

This setting changes only how the time appears on your screen and in notifications — it does not change the actual time your phone is keeping. Some apps may also respect this setting and show time in your chosen format, though not all do.

Frequently Asked Questions

Why does my iPhone keep changing the time back?

Your phone is probably set to Set Automatically on. Every time you connect to a network, it updates the time to match. If you want to keep a manual time, go to Settings > General > Date & Time and turn off Set Automatically. Without it on, your phone will not override your manual setting.

Can I change the time on my lock screen without opening Settings?

No. The lock screen clock is read-only and pulls directly from your system time. You have to go into Settings > General > Date & Time to change it. There is no shortcut or widget that lets you adjust the time from the home screen or lock screen.

What happens to my alarms if I change the clock time?

Your alarms stay set for the same clock time you chose. If you set an alarm for 7 AM and then manually change your clock to show 9 AM, the alarm will go off when your phone's clock reaches 7 AM — which is now two hours away. Alarms are tied to the clock time itself, not to a fixed point in real time.

Does changing the time affect my iPhone's battery or performance?

No. Changing the time or time zone does not drain your battery or slow down your phone. The only performance cost is the brief moment when your phone updates the time automatically after you cross a time zone or when daylight saving time changes — and that cost is negligible.

Can I set different times for different apps?

No. All apps on your iPhone use the same system clock. You cannot set one app to show a different time than another. If you need an app to think it is a different time, you have to change your phone's clock time, which affects everything on the phone.