The quickest way to change your computer's time
The fastest way to change your computer's time depends on whether you use Windows or Mac. On Windows, click the clock in the bottom right corner of your screen, then click "Change date and time settings." On Mac, click the clock in the top right corner, select "Date & Time," then click the lock icon and enter your password to make changes. Both systems let you set the time manually or have the computer update it automatically from the internet.
Most people leave automatic time updates turned on, which means your computer syncs with internet time servers and corrects itself without you doing anything. If your time is consistently wrong even with automatic updates on, your computer's internal battery may be failing — that is a hardware issue that requires professional repair.
Key Takeaways
- Windows users click the clock in the taskbar and select "Change date and time settings" to adjust the time manually or enable automatic updates.
- Mac users click the clock in the menu bar, open "Date & Time," unlock the settings with their password, and choose automatic or manual time setting.
- Automatic time updates are the default on both systems and sync your computer with internet time servers so you do not have to adjust manually.
- If your time keeps resetting to the wrong value even with automatic updates on, your computer's internal clock battery may need replacement by a technician.
How to change the time on Windows 10 and Windows 11
On Windows, the clock sits in the bottom right corner of your taskbar. Click it once. A small panel will pop up showing your current date and time. Below that, you will see a link that says "Change date and time settings" — click that link.
A new window will open called "Date & time." At the top, you will see a toggle labeled "Set time automatically." If that toggle is already on (it appears blue and switched to the right), your computer is already syncing with an internet time server and you do not need to do anything. If it is off, turn it on by clicking the toggle. Your computer will then fetch the correct time from the internet within a few seconds.
If you need to set the time manually instead, turn off the "Set time automatically" toggle first. Then click the button that says "Change" under the "Set the date and time manually" section. A new window will appear where you can type in the correct date and time. Enter the values and click "Change." Your computer will now use the time you entered.
How to change the time on Mac
On Mac, the clock appears in the top right corner of your menu bar. Click it. A dropdown menu will show your current date and time. At the bottom of that menu, click "Date & Time Preferences." This opens the System Preferences window to the Date & Time section.
You will see a lock icon in the bottom left corner of the window. Click it and enter your Mac password when prompted. Once unlocked, you can make changes. Look for a checkbox labeled "Set date and time automatically." If it is checked, your Mac is already syncing with an internet time server. If it is unchecked, check it to turn on automatic updates.
To set the time manually on Mac, leave the automatic setting unchecked. Then click directly on the date or time field and type in the correct values. Your Mac will use the time you entered. You can also click the lock icon again to lock the settings when you are finished.
Why your computer's time might be wrong
If your computer's time is consistently off by the same amount — for example, always one hour behind — the most common cause is that your time zone setting is incorrect. Check your time zone in the same Date & Time settings window where you adjust the time. Make sure it matches the region where you actually are.
If your time drifts slowly over days or weeks, or if it resets to a very old date (like 2010 or 2015) every time you restart, your computer's internal clock battery is likely failing. This battery keeps the system clock running even when the computer is powered off. When it dies, the computer loses track of time. You will need to take your computer to a repair technician to have the battery replaced.
If you use automatic time updates and your computer still shows the wrong time, restart your computer. Sometimes the time sync service needs a fresh start. If the problem persists after a restart, check that your internet connection is working — automatic updates require an active connection to reach the time servers.
Automatic versus manual time setting
Automatic time setting is the better choice for most people. Your computer connects to Network Time Protocol (NTP) servers — these are internet-based clocks maintained by organizations like the U.S. National Institute of Standards and Technology. Your computer checks these servers regularly and adjusts itself to stay accurate. You never have to think about it.
Manual time setting is useful only if your internet connection is unreliable or if you need your computer to show a time that differs from your actual time zone for testing purposes. In everyday use, leave automatic updates on. It requires no maintenance and keeps your time accurate to within a fraction of a second.
Changing your time zone without changing the time
If you travel to a different time zone or move to a new region, you can update your time zone setting without manually adjusting the clock. On Windows, open Date & Time settings, scroll down to "Time zone," and click the dropdown to select your new zone. Your computer will automatically adjust the displayed time to match.
On Mac, open Date & Time Preferences, click the "Time Zone" tab, and select your new location from the list. You can also click on the map to choose your time zone visually. Your Mac will update the displayed time when ready.
If you have automatic time updates turned on, changing your time zone is all you need to do. Your computer will handle the rest. If you use manual time setting, you will need to adjust the time itself as well as the zone.
Syncing time across multiple devices
If you use multiple computers or devices, they will all stay synchronized automatically as long as automatic time updates are enabled on each one. They all connect to the same NTP servers, so they will all show the same time (within a second or two).
If one device is showing a noticeably different time than the others, check that device's automatic time setting first. If it is off, turn it on. If it is already on, restart that device and wait a minute for it to sync. If the problem continues, that device may have a failing internal clock battery.
Frequently Asked Questions
Why does my computer's time reset every time I turn it off?
Your computer has an internal battery that keeps the system clock running when powered off. If the time resets to an old date every restart, that battery is failing and needs replacement. This is a hardware repair that requires a technician.
Can I set my computer to a different time zone than where I actually am?
Yes. In Date & Time settings, you can select any time zone from the dropdown list, and your computer will display the time for that zone. This is sometimes useful for work or testing, but it means your computer will not show your local time.
What if automatic time updates are on but my time is still wrong?
Restart your computer first — the time sync service sometimes needs a fresh start. Check that you have an active internet connection. If the problem persists, verify your time zone setting is correct. If all of those are fine, your internal clock battery may be failing.
Does changing the time affect my files or programs?
Changing the time can affect file timestamps and programs that rely on the system clock, like scheduling software or backup tools. Avoid changing the time unless necessary. If you must change it, do so briefly and then set it back to the correct time as soon as possible.
Can I change the time format from 12-hour to 24-hour?
Yes. On Windows, open Date & Time settings, scroll to "Related settings," and click "Change date and time formats." Select your preferred format from the dropdown. On Mac, open Date & Time Preferences, click the "Time" tab, and choose your format. This changes only how the time is displayed, not the actual time itself.