The fastest way to change your computer's time
On Windows, click the time in the bottom right corner of your screen, then select "Change date and time settings." On Mac, go to System Settings, click "General," then "Date & Time." Both operating systems let you toggle automatic time updates on or off — if your clock is wrong, the automatic setting is usually off or your computer lost internet connection.
If you want to set the time manually instead of letting your computer sync automatically, both Windows and Mac will let you type in the exact hour, minute, and second. The manual route takes about 30 seconds once you reach the time settings screen.
Most people should leave automatic time on. Your computer stays accurate without any work from you, and it adjusts for daylight saving time without you having to remember. Manual time setting is useful only if you need a specific time for testing, troubleshooting, or working across time zones temporarily.
Key Takeaways
- Windows users click the system clock in the bottom right corner and select "Change date and time settings" to reach the time controls.
- Mac users open System Settings, go to "General," then "Date & Time" to adjust the clock.
- Automatic time synchronization keeps your clock accurate without any action from you and handles daylight saving time changes automatically.
- Manual time changes take effect when ready but will revert if automatic synchronization is enabled.
- If your time is consistently wrong, check that automatic updates are on and that your computer has an active internet connection.
How to change the time on Windows 10 and Windows 11
Right-click the time display in the bottom right corner of your taskbar. A menu will appear with several options. Select "Adjust date/time" or "Change date and time settings" — the exact wording depends on your Windows version, but both lead to the same place.
The Settings window will open to the Date & Time page. You will see a toggle for "Set time automatically." If this toggle is on (blue), your computer is syncing with an internet time server and you cannot manually change the time — Windows will override any manual entry. Turn the toggle off first if you want to set a custom time.
Once automatic time is off, a new option called "Change" will appear below the toggle. Click it, and a dialog box will let you enter the exact date, hour, minute, and second. Type in your desired time and click "Change" to save it. The new time takes effect when ready on your screen and in your system.
How to change the time on Mac
Click the Apple menu in the top left corner and select "System Settings" (or "System Preferences" on older macOS versions). In the sidebar, click "General," then look for "Date & Time" in the main panel.
You will see a checkbox labeled "Set date and time automatically." If this box is checked, your Mac is synchronizing with Apple's time servers and will not accept manual changes. Uncheck the box to enable manual time entry.
Once automatic time is off, the date and time fields become editable. Click on the time field and type the hour and minute you want. Click on the date field to change the date if needed. Your changes save automatically when you close the Settings window.
Why your computer's time might be wrong
The most common reason is that automatic time synchronization is turned off. This can happen if you disabled it intentionally, if a software update reset your settings, or if your computer has not connected to the internet in a while. Turning automatic time back on solves the problem in most cases.
A dead or failing CMOS battery can also cause time drift on older computers. The CMOS battery is a small coin-cell inside your computer that keeps the system clock running when the power is off. If your time resets to the same wrong value every time you restart, the battery may be failing. This requires opening your computer or taking it to a repair shop.
If your computer is on a corporate network, your IT department may have locked the time settings so employees cannot change them. In that case, you will not see the option to disable automatic time, and you should contact your IT support team if the time is incorrect.
When to use automatic time versus manual time
Leave automatic time on for everyday use. It keeps your clock accurate without any work, handles daylight saving time changes automatically, and ensures your timestamps on files and emails are correct. There is no downside to automatic time unless you need your computer to show a different time for testing or development work.
Use manual time only when you are testing software that depends on the system clock, troubleshooting time-related issues, or temporarily working in a different time zone. Once you finish, turn automatic time back on so your clock stays accurate going forward.
If you travel frequently and want your computer to show local time, do not change the system time manually. Instead, change your time zone in the same settings window. Your system clock will stay synchronized with the internet, but your displayed time will match your location.
What happens after you change the time
Any change you make takes effect when ready. Programs running on your computer will see the new time right away. Files you create or modify will be timestamped with the new time, which can cause confusion if you set the time to the past — your new files may appear older than files created before the change.
If automatic time synchronization is on, your manual change will be overwritten the next time your computer syncs with an internet time server, usually within a few minutes. This is why you must turn off automatic time before making a manual change if you want it to stick.
Restarting your computer does not reset the time you set manually, as long as your computer's internal battery is working. The time persists until you change it again or until automatic synchronization corrects it.
Frequently Asked Questions
Why does my computer time change back after I set it?
Automatic time synchronization is still on. Go back to Date & Time settings and turn off the "Set time automatically" toggle on Windows or uncheck "Set date and time automatically" on Mac. Your manual time will then stay in place until you change it again.
Can I set different times for different programs?
No. The system time is global — all programs on your computer use the same clock. If you need one program to see a different time, you must change the system time, which affects everything. Some development tools have built-in time simulation features, but those are separate from the system clock.
Does changing the time affect my internet connection?
Not directly. However, if you set the time far in the past or future, some websites and services may refuse to connect because they think your computer's certificate is invalid. Setting the time to within a few hours of the correct time avoids this problem.
What if the time settings are grayed out and I cannot change them?
You may not have administrator rights on your computer. On Windows, right-click the Settings app and select "Run as administrator," then try again. On Mac, you may need to unlock the Date & Time pane by clicking the lock icon in the bottom left. If you are on a work computer, your IT department may have locked these settings.
How do I change my time zone without changing the actual time?
In the same Date & Time settings window, look for a "Time zone" dropdown separate from the time itself. Select your new time zone, and your displayed time will adjust automatically while the system clock stays synchronized with the internet. This is the correct way to handle time zones.