Your phone usually changes its clock automatically, and you can turn that off

Most phones — whether Android or iPhone — sync their clock to a network time server the moment they connect to the internet. This happens in the background without asking you. The phone receives the exact time from your carrier or a public time server, updates its internal clock, and adjusts the display. On iPhones, this is called "Set Automatically" under Settings > General > Date & Time. On Android phones, it's "Automatic date and time" under Settings > System > Date & Time or Settings > Date & Time, depending on your phone's version.

You can disable this feature on both platforms and set the time manually instead. Turning it off means your phone will keep whatever time you set it to, even if that time drifts away from reality. This matters for security and privacy because automatic time sync reveals your location to your carrier and the time server, and because some security features (like certificate validation for encrypted connections) depend on your clock being accurate.

Key Takeaways

  • Automatic time sync is enabled by default on both iPhone and Android, and it sends your location data to your carrier and time servers each time it updates.
  • You can disable automatic time sync in your phone's date and time settings and set the time manually, though your clock will gradually drift if you do not update it yourself.
  • Keeping automatic time sync on is usually safer for security purposes, because many encrypted connections and app features rely on your clock being correct.
  • If you disable automatic sync, your phone will still show the correct time most of the time — it only drifts noticeably over weeks or months of no updates.

How automatic time sync works on your phone

When you turn on your phone or connect to Wi-Fi or cellular data, your phone contacts a time server — usually operated by your carrier, Google, Apple, or a public service like NIST (the National Institute of Standards and Technology). The server sends back the exact current time, and your phone updates its internal clock to match. This happens silently, usually once per day or whenever you reconnect to the internet after being offline.

The phone does this because its internal clock — the battery-backed clock that keeps time even when the phone is off — drifts over time. A phone's clock can lose or gain several seconds per week depending on temperature and the age of the battery. Without periodic corrections, your clock would be noticeably wrong within a month. Automatic sync keeps it accurate without you having to think about it.

What data your phone sends when it syncs the time

When your phone contacts a time server, it reveals your approximate location. If you are on cellular data, your carrier already knows your location from which cell tower you are connected to, so the time sync does not add much new information. If you are on Wi-Fi, the time server can estimate your location based on the IP address your internet provider assigned to you — usually accurate to within a city or neighborhood, sometimes more precise.

Your phone also sends a request that identifies it as a phone (rather than a computer or other device), and sometimes identifies the operating system version. This information is logged by the time server operator and can be used to build a profile of when and where you are online. If you are concerned about location tracking, disabling automatic time sync reduces one source of location leaks, though it does not eliminate them — your carrier and internet provider still know where you are.

How to turn off automatic time sync on iPhone

Open Settings, then tap General. Scroll down and tap Date & Time. You will see a toggle labeled "Set Automatically" — it is usually on (green). Tap it to turn it off. Once you do, a new field appears labeled "Time Zone" and another field for the time itself. You can now set the time manually by tapping the time field and using the scroll wheels to choose the hour and minute.

If you turn off automatic sync, check your time occasionally — perhaps once a week — and update it manually if it has drifted more than a few minutes. Your phone's clock will continue to drift slowly even when it is off, so you may need to adjust it every few weeks depending on how much you use the phone.

How to turn off automatic time sync on Android

The exact path depends on your phone's manufacturer and Android version. On most recent Android phones, open Settings, then tap System (or About Phone on some models), then Date & Time. You will see a toggle labeled "Automatic date and time" or "Use network-provided time" — tap it to turn it off. Once disabled, a new field appears where you can set the time manually.

Some Android phones from Samsung, OnePlus, or other manufacturers may have the setting in a different location. If you cannot find it in System settings, try searching for "date and time" in the Settings search bar at the top of the app. Once you find the toggle, the process is the same: turn it off and set the time manually using the fields that appear.

Why keeping automatic sync on is usually the safer choice

Many security features on your phone depend on your clock being correct. When you visit a website over HTTPS (the find version), your phone checks the website's security certificate to make sure it is valid. Part of that check involves comparing the certificate's expiration date to your phone's current time. If your clock is wrong — especially if it is set to a date in the past — your phone may reject valid certificates and refuse to connect to legitimate websites.

Apps that use two-factor authentication (like banking apps or password managers) also rely on your clock being accurate. These apps generate time-based codes that expire after 30 seconds. If your phone's clock is significantly wrong, the codes you generate will not match what the server expects, and you will not be able to log in. For most people, the privacy benefit of disabling automatic time sync is smaller than the security risk of having an inaccurate clock.

The trade-off between privacy and security

Disabling automatic time sync gives you slightly more privacy by reducing the number of times your phone reveals your location to a time server. But it creates a real security risk: your phone becomes more vulnerable to man-in-the-middle attacks (where someone intercepts your connection and pretends to be a legitimate website), and you may be locked out of apps that depend on accurate time.

If you are concerned about location tracking, there are more effective steps you can take: turn off location services for apps that do not need it, use a VPN to hide your IP address from time servers and websites, or disable cellular data and Wi-Fi when you are not using them. These steps reduce your location exposure more significantly than disabling automatic time sync, and they do not create the security problems that an inaccurate clock does.

Frequently Asked Questions

Will my phone's clock stop working if I turn off automatic sync?

No. Your phone's internal clock will continue to keep time, but it will gradually drift — usually losing or gaining a few seconds per week. Over a month, it might be off by a minute or two. The clock will not stop; it will just become less accurate over time.

Can I set my phone's time to something other than the real time?

Yes, you can set it to any time you want. However, doing so will break many apps and security features. Banking apps, password managers, and websites with HTTPS certificates will stop working correctly. It is not recommended unless you have a specific reason to do it.

Does turning off automatic time sync hide my location from my phone company?

No. Your carrier knows your location from which cell tower you are connected to, regardless of whether automatic time sync is on or off. Disabling time sync only prevents time servers from learning your location — it does not hide you from your carrier.

What happens if my phone's time is very wrong when I try to use an app?

Apps that use time-based authentication (like two-factor codes) will not work. Websites with HTTPS certificates may refuse to load. You will need to manually correct your phone's time to fix these problems. This is why keeping automatic sync on is usually safer.

Do I need to turn off automatic time sync to protect my privacy?

Not necessarily. Disabling it provides a small privacy benefit, but using a VPN, turning off location services, or disabling Wi-Fi and cellular data when you are not using them are more effective ways to reduce tracking. Automatic time sync is a minor source of location leaks compared to these other channels.