The fastest way to change your Mac's time

Click the clock in the top-right corner of your screen, then click "Date & Time Preferences" in the menu that appears. In the window that opens, uncheck "Set date and time automatically" if it is checked. Now you can click the date and time fields and type in the correct values directly. When you are done, close the window — your Mac saves the change right away.

If your Mac is set to update automatically (the default), you will not see editable time fields. That automatic setting syncs your time with Apple's servers, which is usually the right choice because it keeps your clock accurate without you having to think about it. But if you need to override it temporarily or permanently, unchecking that box gives you manual control.

Key Takeaways

  • Open Date & Time Preferences by clicking the clock in your menu bar, then uncheck "Set date and time automatically" to edit the time manually.
  • Your Mac's time zone is set in the same preferences window and controls how your calendar, email, and meeting times display.
  • If you travel frequently or work across time zones, you can change your time zone without changing the actual time your Mac displays.
  • Restarting your Mac or signing out and back into your Apple ID can fix a time that keeps resetting or jumping to the wrong value.

Where to find the date and time settings

The clock lives in your menu bar at the top right of the screen. Click it once and a small menu drops down showing the current date and time. At the bottom of that menu is a link that says "Date & Time Preferences" — click that to open the full settings window.

Alternatively, you can reach the same window through System Settings. Click the Apple menu in the top-left corner, select "System Settings," then scroll down the left sidebar and click "General." In the right panel, click "Date & Time." Both routes open the same preferences, so use whichever feels faster to you.

Turning off automatic time updates

By default, your Mac has "Set date and time automatically" turned on. This means your computer contacts Apple's time servers and adjusts itself to match, which keeps your clock accurate without any work from you. The time zone is also set automatically based on your location if you have location services turned on.

To make manual changes, you must uncheck this box first. Once you do, the date and time fields become clickable and editable. You can then type in the correct date, hour, minute, and second. The time zone field also becomes editable, so you can change that separately if needed.

Changing your time zone without changing the time

Your time zone setting controls how your Mac displays the time and how it schedules calendar events and meeting reminders. If you travel to a different time zone or move, you may want to change this setting so your calendar shows the correct local time.

In Date & Time Preferences, click the "Time Zone" tab. A map appears with your current location marked. You can click on a different region of the map, or type a city name into the search box at the top. When you select a new time zone, your Mac automatically adjusts what time it displays — so if it was 3 p.m. in New York and you switch to Los Angeles time, it will now show 12 p.m. The actual moment in time does not change; only how your Mac labels it changes.

What to do if your Mac keeps resetting the time

If you set the time manually but it keeps jumping back to a different value, your Mac is likely trying to re-enable automatic updates. This can happen if a software update runs in the background or if your Mac syncs with your Apple ID account, which stores time settings in iCloud.

First, make sure "Set date and time automatically" stays unchecked. If it keeps turning itself back on, restart your Mac completely — shut it down, wait a few seconds, then turn it back on. If the problem continues, sign out of your Apple ID (go to System Settings > [Your Name] > "Sign Out"), restart again, and then sign back in. This clears any conflicting sync data and usually resolves the issue.

If your time is wrong but you have automatic updates on, the problem is usually a network connection issue. Your Mac cannot reach the time server, so it cannot update. Restart your Mac and make sure you are connected to the internet, then wait a minute or two for the automatic update to run.

Why your Mac's time matters

Your Mac's internal clock affects more than just what time it shows you. It controls when your calendar events trigger notifications, when your email client checks for new messages, when scheduled backups run, and when your Mac applies security certificates to websites. If the time is significantly wrong, your calendar reminders may fire at the wrong moment, or your browser may refuse to load certain websites because it thinks the security certificate has expired.

For this reason, keeping your Mac's time accurate is worth the small effort. Automatic time updates are the easiest solution and are turned on by default. If you do need to change the time manually, do so through Date & Time Preferences rather than trying to edit the system clock through other means.

Frequently Asked Questions

Can I change the time on my Mac without unchecking automatic updates?

No. When "Set date and time automatically" is on, the time fields are locked and read-only. Your Mac will override any manual change you try to make within seconds. You must uncheck the box first, make your change, and then decide whether to turn automatic updates back on or leave it off.

Will changing my time zone affect my calendar events?

Your calendar events will shift to show the correct time in the new time zone. If you had a meeting scheduled for 3 p.m. Eastern time and you switch to Pacific time, the calendar will now show 12 p.m. The meeting itself does not change — only how your Mac displays it. If you are joining a meeting with people in other time zones, make sure everyone is clear on the actual time the meeting starts, not just what their local clock shows.

What if I need to set a different time zone for just one event?

You cannot change your Mac's system time zone for a single event. However, when you create or edit a calendar event in Calendar or other apps, you can usually set the time zone for that specific event in its details. This way the event shows the correct time even if your Mac's system time zone is different. Check your calendar app's settings for a "Time Zone" option when editing an event.

Does changing the time on my Mac affect my backups?

If you use Time Machine, changing your Mac's time can confuse the backup schedule. Time Machine uses your Mac's clock to decide when to run backups. If you set the time backward significantly, Time Machine may think a backup is overdue and run one immediately. If you set it forward, it may skip a scheduled backup. After you change the time, let your Mac sit for a few minutes so Time Machine can catch up with the new schedule.