The fastest way to reset your computer's time

The quickest method depends on your operating system. On Windows, right-click the clock in the bottom-right corner of your taskbar and select "Adjust date and time." On macOS, open System Preferences, click "Date & Time," and make your changes there. Both systems also let you set the time to update automatically from the internet, which prevents the problem from happening again.

If your clock is only a few minutes off, automatic synchronization will fix it within the hour. If it is hours or days wrong, you will need to adjust it manually first, then turn on automatic updates. The process takes less than two minutes either way.

Key Takeaways

  • Windows users right-click the system clock and select "Adjust date and time" to change the time manually or turn on automatic updates.
  • macOS users open System Preferences, click "Date & Time," and can toggle automatic time zone and time updates in the same window.
  • Turning on automatic time synchronization prevents your clock from drifting and means you will rarely need to reset it manually again.
  • If your time is drastically wrong, check that your system date is correct before adjusting the time, since the two are linked.
  • A dead or dying CMOS battery in older computers can cause the clock to reset every time you shut down, requiring a hardware replacement.

Resetting the time on Windows 10 and Windows 11

Open the Settings app by pressing the Windows key and typing "settings," then press Enter. Click "Time & language" on the left side, then "Date & time" in the main panel. You will see your current date and time displayed at the top.

To change the time manually, toggle off "Set time automatically" first. Once that switch is off, a new option called "Change" will appear below it. Click "Change," enter the correct time in the window that opens, and click "OK." Your system will update when ready.

After you have corrected the time, turn "Set time automatically" back on. This tells Windows to sync with internet time servers regularly, so your clock stays accurate without you having to adjust it again. You can also check the "Set time zone automatically" toggle on the same page if you have moved to a different region.

Resetting the time on macOS

Click the Apple menu in the top-left corner and select "System Preferences" (or "System Settings" on macOS Ventura and newer). Search for "Date & Time" in the search bar or scroll down to find it, then click it.

The "Date & Time" window shows your current date and time. If you need to change it manually, click the lock icon in the bottom-left corner and enter your password to unlock the settings. Then click the date and time fields to edit them directly. After you finish, click the lock icon again to save your changes.

Below the date and time fields, you will see a checkbox for "Set date and time automatically." Turn this on if it is not already checked. macOS will then sync your clock with Apple's time servers several times per day, keeping it accurate without any action from you.

Why your computer's time keeps drifting

Every computer has an internal clock powered by a small battery called the CMOS battery. This battery keeps the clock running even when your computer is shut down. Over time, this battery weakens and eventually dies, causing the clock to reset or lose time every time you power off the machine.

If your clock is correct when you turn on your computer but wrong again the next day, the CMOS battery is likely failing. On desktop computers, a technician can replace it for under fifty dollars. On laptops, the process is more involved and may cost more, so it is often worth checking whether automatic time synchronization can work around the problem first.

If you turn on automatic time updates and your clock still drifts within hours, the CMOS battery is probably the culprit. At that point, a hardware repair is the only permanent fix.

Turning on automatic time synchronization

Automatic time synchronization is the best long-term solution because it means your clock will stay accurate without any effort on your part. Both Windows and macOS check internet time servers multiple times per day and adjust your system clock if it has drifted.

On Windows, the setting is called "Set time automatically" and lives in Settings > Time & language > Date & time. On macOS, it is "Set date and time automatically" in System Preferences > Date & Time. Both are toggle switches that you straightforward turn on.

Your computer needs an internet connection for this to work, but it does not need to be connected all the time. The synchronization happens in the background whenever you are online, so even if your internet drops for a few hours, the clock will re-sync the next time you connect.

What to do if you cannot access the time settings

If you are locked out of your user account or cannot reach the Settings app, you may still be able to change the time from the lock screen. On Windows, click the time display in the bottom-right corner of the lock screen. A calendar and clock widget will appear, and you can click on the time to open a quick adjustment menu.

On macOS, if you are at the login screen, you cannot change the time without logging in first. However, you can restart your computer and hold Command + Option + R during startup to enter Recovery Mode, where you can access Date & Time settings from the Utilities menu. This is rarely necessary unless your account password is lost.

If you are having trouble with either method, restart your computer and try again. Sometimes the settings app needs a fresh start to respond properly.

Checking your internet time server connection

If you have turned on automatic time synchronization but your clock is still wrong, your computer may not be reaching the time server. On Windows, open Command Prompt by pressing Windows key + R, typing "cmd," and pressing Enter. Type "w32tm /query /status" and press Enter. This shows whether your computer is syncing with a time server and when the last sync occurred.

On macOS, open Terminal (search for it in Spotlight by pressing Command + Space) and type "sntp -sS time.apple.com" then press Enter. If the command succeeds, your computer can reach Apple's time server. If it fails, a firewall or network issue may be blocking the connection.

If your computer cannot reach the time server, check that you are connected to the internet and that any firewall software is not blocking the connection. Restarting your router and computer often fixes temporary network issues that prevent time synchronization.

Frequently Asked Questions

Why does my computer's time reset every time I shut it down?

This almost always means your CMOS battery is dead or dying. The CMOS battery keeps your system clock running when the computer is powered off. When it fails, the clock resets to a default time each time you restart. On a desktop, replacing the CMOS battery costs under fifty dollars and takes a technician about thirty minutes. On a laptop, the cost and time vary depending on the model.

Can I change the time without being an administrator?

On Windows, you need administrator rights to change the system time. If you are not an administrator, ask whoever manages your computer to make the change or grant you administrator access. On macOS, you need to enter your password, which is required even if you are the main user of the computer.

What if my computer's time is correct but the time zone is wrong?

On Windows, go to Settings > Time & language > Date & time and toggle on "Set time zone automatically." On macOS, open System Preferences > Date & Time and check "Set time zone automatically." Both systems will detect your location and update the time zone within a few minutes.

Does changing the system time affect my files or programs?

Changing the time can affect file timestamps and programs that rely on accurate timing, such as backup software or scheduled tasks. If you are changing the time by more than a few minutes, it is best to do it when no programs are running. Turning on automatic time synchronization means you will rarely need to make large adjustments.

What if automatic time sync is on but my clock is still wrong?

First, check that you are connected to the internet. Then restart your computer and wait a few minutes for the sync to complete. If the problem persists, your CMOS battery may be failing, or a firewall may be blocking the connection to the time server. Try restarting your router as well, since network issues sometimes prevent synchronization.