Where to find your clock and why it matters

Your computer's clock runs in the background and affects more than just telling time. If it drifts too far from the actual time, your emails may show the wrong date, security certificates can fail, and scheduled tasks won't run when they should. Changing the clock is straightforward on Windows and Mac, and takes less than a minute once you know where to look.

The clock lives in different places depending on your operating system. On Windows, it's in the bottom right corner of your screen in the taskbar. On Mac, it's in the top right corner of the menu bar. Both systems let you adjust it directly from there, though the steps differ slightly.

Key Takeaways

  • On Windows, right-click the clock in the taskbar and select "Adjust date/time" to open the settings panel where you can change the time manually or let Windows sync automatically.
  • On Mac, click the clock in the menu bar, select "Open Date & Time Preferences," and enter your password to change the time or enable automatic synchronization.
  • Most computers can sync their clock automatically with internet time servers, which is more reliable than setting the time by hand.
  • If your clock keeps changing back after you set it, your computer may be overriding your change with automatic sync — check that setting first.

Changing the clock on Windows

Start by right-clicking the clock in the bottom right corner of your taskbar. A small menu will pop up. Look for the option that says "Adjust date/time" or "Adjust date and time" and click it. This opens the Settings app to the Date & Time panel.

Once the panel opens, you'll see a toggle labeled "Set time automatically" near the top. If this toggle is already on (it will be blue), Windows is syncing your clock with an internet time server and you don't need to do anything — it will correct itself. If you want to set the time manually instead, turn this toggle off first.

After you turn off automatic sync, a new option appears below it: "Set the time manually." Click that option. A box will appear where you can type in the correct time. Enter the hour, minute, and second, then click the checkmark or press Enter to save. Your clock will now show the time you entered.

Changing the clock on Mac

Click the clock in the top right corner of your menu bar. A dropdown menu will appear. At the bottom of this menu, click "Open Date & Time Preferences." A window will open showing your current date and time settings.

You'll see a lock icon in the bottom left corner of this window. Click it and enter your Mac password when prompted — this unlocks the settings so you can make changes. Once unlocked, you can manually adjust the time by clicking in the time field and typing the correct hour, minute, and second.

If you want Mac to set the time automatically instead, check the box next to "Set date and time automatically." When this is on, your Mac will sync with an internet time server and keep itself accurate without your help. This is the most reliable option for most users.

Using automatic time sync instead of manual changes

Both Windows and Mac offer automatic synchronization with internet time servers, and this is almost always better than setting the time by hand. When automatic sync is on, your computer contacts a time server on the internet several times a day and adjusts itself if it has drifted. You never have to think about it again.

Automatic sync is on by default on most computers, which is why many people never have to change their clock at all. If your clock is wrong, the first thing to check is whether automatic sync is turned on. If it is, wait a few minutes — your computer may be in the process of syncing. If it's off, turn it back on and let your computer correct itself rather than typing in the time manually.

The only reason to turn off automatic sync is if your computer's clock needs to be different from the real time for a specific reason — for example, if you're testing software that depends on a particular date. In normal use, leave it on.

What to do if the clock keeps changing back

If you set the time manually and it changes back a few minutes later, automatic sync is almost certainly the cause. Your computer is overriding your manual change with the time from the internet server. This is actually the correct behavior — it means your computer is protecting itself from a wrong clock.

If you want the time to stay as you set it, you need to turn off automatic sync first, then change the clock. But before you do that, ask yourself whether the automatic time is actually correct. Check your phone, a clock on the wall, or a website that displays the current time. If the automatic time is right and you set it to something else, your computer is doing the right thing by changing it back.

If automatic sync is already off and the clock still won't stay where you set it, your computer's internal battery may be failing. This battery keeps the clock running even when the computer is powered off. A failing battery will cause the clock to lose time or reset. If you suspect this, take your computer to a technician — it's a hardware issue that requires physical repair.

Checking your time zone settings

Sometimes the clock shows the right time but in the wrong time zone. If you've moved to a different part of the country or the world, your computer may still be set to your old location. This won't change the actual time displayed, but it affects how your computer interprets times in emails, files, and scheduled tasks.

On Windows, the time zone setting is in the same Date & Time panel where you change the clock. Look for a dropdown labeled "Time zone" and select the correct one for your current location. On Mac, open Date & Time Preferences the same way, and you'll see a "Time zone" tab at the top of the window. Click it and search for your city or region.

If automatic sync is on, your computer will usually detect your time zone automatically based on your internet connection. But if you've moved recently and the automatic detection hasn't caught up, you can set it manually. This is especially important if you travel frequently or work with people in different time zones.

Frequently Asked Questions

Why does my computer's clock lose time even though automatic sync is on?

Automatic sync corrects your clock several times a day, but if your internet connection drops between syncs, your clock may drift slightly. This is normal and will correct itself the next time your computer connects to the internet. If your clock loses several minutes or hours, your internet connection may be unstable, or your computer's internal clock hardware may be failing.

Can I change the clock format from 12-hour to 24-hour?

Yes. On Windows, go to Settings > Time & Language > Date & Time, scroll down, and click "Change date and time formats." You'll see options for how the time displays. On Mac, open Date & Time Preferences, click the "Time" tab, and choose your preferred format from the dropdown. This changes how the clock appears on your screen but doesn't change the actual time.

What happens if I set my computer's clock to the wrong date?

Your computer will treat that wrong date as real, which can cause problems. Emails will show incorrect dates, security certificates may fail, and scheduled backups or updates might not run. If you accidentally set the date wrong, change it back as soon as you notice. If automatic sync is on, your computer will correct itself automatically within a few minutes.

Do I need to restart my computer after changing the clock?

No. Changes to the clock take effect when ready. You don't need to restart, and restarting won't help if the clock is still wrong. If you've changed the clock and it's still showing the wrong time after a few minutes, check whether automatic sync is overriding your change.