The quickest way to set your iPhone's clock
Open Settings, tap General, then tap Date & Time. Turn on "Set Automatically" if you want your phone to sync with your carrier's time, or turn it off and set the time manually by tapping the time field. Most people leave it on — your phone stays accurate without any work on your part.
If you turned off automatic time, you'll see hour and minute fields appear. Tap each one and use the scroll wheels to set the correct time. When you're done, tap General at the top left to go back, and your new time takes effect when ready.
The date updates the same way. With "Set Automatically" on, your iPhone pulls the correct date from your network. If you turn it off, a Date field appears below the time, and you can adjust the month, day, and year using the same scroll wheels.
Key Takeaways
- The fastest method is Settings > General > Date & Time, then toggle "Set Automatically" on to let your phone handle it.
- If you turn off automatic time, scroll wheels appear for the hour, minute, month, day, and year — adjust each one separately.
- Manual time changes take effect when ready and stay until you change them again or turn automatic sync back on.
- Your iPhone syncs time with your cellular carrier when automatic is on, so you don't need to adjust it when traveling between time zones.
- If the time keeps reverting to the wrong setting, check that "Set Automatically" is actually on, because some updates can reset it.
Why your iPhone might show the wrong time
The most common reason is that "Set Automatically" got turned off, either by accident or during a software update. Your phone then stays frozen at whatever time you last set it to, even if hours pass. Check Settings > General > Date & Time and look for that toggle — if it's off (gray), tap it to turn it back on (green).
A second reason is that your phone lost connection to your carrier's network. If you're in airplane mode, on Wi-Fi only without cellular, or in an area with no signal, your iPhone can't fetch the correct time. Turn off airplane mode or move to an area with cell service, and the time will update within a minute or two.
If you manually set the time and then forgot you did it, that's also common. Go back to Settings > General > Date & Time and check whether "Set Automatically" is on or off. If it's off and the time is wrong, turn it back on.
Setting time manually when automatic sync doesn't work
Sometimes you need to set the time by hand — for example, if you're testing a feature that depends on a specific time, or if your phone is in a location where the network time is unreliable. Go to Settings > General > Date & Time, turn off "Set Automatically", and the time and date fields will appear.
Tap the time field. A scroll wheel interface opens with separate wheels for hours and minutes. Scroll up or down on each wheel until the numbers match what you want. The hour wheel shows 1 through 12 (or 0 through 23 if you have 24-hour time turned on in your region settings), and the minute wheel shows 0 through 59 in five-minute increments.
After you set the time, tap the date field below it. The same scroll wheel interface appears, but now with wheels for month, day, and year. Adjust each one to the date you need. When you're finished, tap General at the top left to close the settings, and your changes save automatically.
Changing your time zone without changing the clock
If you travel to a different time zone and want your iPhone to update automatically, you don't need to do anything — "Set Automatically" handles it. Your phone will detect the new time zone from your carrier and adjust the clock within a few minutes of landing.
If you want to see what time zone your phone thinks it's in, go to Settings > General > Date & Time and look for the time zone field near the bottom. It shows your current region. When you travel, this field updates automatically if "Set Automatically" is on.
If you're in a place where the automatic detection isn't working, you can set the time zone manually. Turn off "Set Automatically", and a time zone field appears. Tap it and type the name of your city or region — your iPhone will show matching time zones, and you can tap the one you want. Your clock will adjust to match that zone.
Why 24-hour time might change how your clock looks
Some regions and personal preferences use 24-hour time (also called military time) instead of 12-hour time with AM and PM. If your iPhone is set to 24-hour time, the hour wheel in the time picker will show 0 through 23 instead of 1 through 12, and your clock will display 13:00 instead of 1:00 PM.
To change between 12-hour and 24-hour format, go to Settings > General > Language & Region, scroll down, and look for "Time Format". Tap it and choose either 12-Hour or 24-Hour. This setting affects how the time appears everywhere on your phone — in the status bar, on your lock screen, in the clock app, and in the time picker when you manually set the time.
Changing the time format does not change what time it actually is — it only changes how your phone displays it. If it's 1:30 PM and you switch to 24-hour format, your phone will show 13:30, but the actual time hasn't moved.
What happens when you restart your iPhone
If you manually set the time and then restart your iPhone, the time you set stays in place — it doesn't revert. However, if "Set Automatically" is on, your phone will re-sync with your carrier's time during startup, which may overwrite any manual changes you made.
This is usually what you want. If you manually set the time to test something and then restarted, the automatic sync brings you back to the correct time. But if you intentionally set a custom time for a reason, make sure "Set Automatically" is off before you restart, or your change will be lost.
Frequently Asked Questions
Does changing the time on my iPhone affect my alarms?
Yes. If you set the time backward, an alarm that was supposed to go off in five minutes will go off when ready or not at all, depending on how far back you moved the time. If you set the time forward, alarms scheduled for times you've now passed won't go off until the next day. Avoid manually changing the time if you have alarms set for soon.
Can I set a different time for different apps?
No. The time on your iPhone is system-wide — every app sees the same clock. If you change the time in Settings, all apps see that change. Some apps may have their own timers or countdowns, but they all run on top of your phone's main clock.
What if my iPhone keeps changing the time back to automatic?
This usually means a software update reset your settings. Go to Settings > General > Date & Time and check the "Set Automatically" toggle. If it's on and you want manual time, turn it off. If it keeps turning itself back on, restart your phone and try again — sometimes a restart clears a stuck setting.
Does turning off automatic time drain my battery?
No, not noticeably. Your iPhone uses very little power to keep track of time, whether it's syncing with the network or running on its own internal clock. The difference in battery life is too small to measure.
Can I set the time to a date in the future or past?
Yes, you can set your iPhone's clock to any date and time you want by turning off "Set Automatically" and using the scroll wheels. However, setting the time far into the past or future can confuse some apps, break certificate validation, or cause other unexpected behavior. Only do this if you have a specific reason.