macOS · System Info

Set the Date, Time & Time Zone on Mac

Date & Time settings keep your Mac's clock accurate by syncing automatically with a network time server, or let you set the date, time, and time zone manually when automatic detection isn't appropriate.

How to open Date & Time

  1. Open System Settings → General → Date & Time.
  2. Turn on 'Set time and date automatically' and choose a network time server if needed.
  3. Turn on 'Set time zone automatically using current location', or set your time zone manually.
  4. Choose 24-hour time if preferred.

What you should know

  • 'Set time and date automatically' uses a network time server to keep the clock accurate to the second.
  • Time zone can also be detected automatically based on your current location, or set manually.
  • Manual time and date entry is available for Macs without reliable internet access.
  • A 24-hour time format toggle is available separately from the date and time itself.
  • Menu bar clock display options (like showing the date or seconds) are configured from Control Center settings, not this pane.

An incorrect date or time can break certificate validation, causing HTTPS websites, App Store sign-in, or iCloud sync to fail with confusing errors — this is one of the first things worth checking during unexplained login or connectivity problems.

Why it matters

An accurate system clock underpins far more than the menu bar display — secure connections, App Store and iCloud authentication, calendar invitations, and file timestamps all depend on your Mac's time being correct. A clock that's even a few minutes off can cause HTTPS certificate errors or failed two-factor authentication codes, since both rely on tightly synchronized time between your Mac and the server it's talking to. Automatic time zone detection also saves the easy-to-forget step of manually adjusting your clock after traveling, preventing missed meetings from a stale time zone.

Best practices

  • Leave 'Set time and date automatically' turned on unless you have a specific reason (like an isolated network) to set it manually.
  • Enable automatic time zone detection if you travel regularly, so meeting times adjust correctly without manual intervention.
  • Double-check the date and time first when troubleshooting HTTPS, App Store, or iCloud sign-in errors, since a wrong clock is a common invisible cause.
  • Use a corporate-provided time server address if your organization requires one, rather than the public Apple default.

Common problems and fixes

Websites or the App Store show certificate or security errors.
Check Date & Time settings first — an incorrect clock breaks certificate validation; turn on 'Set time and date automatically' and reconnect to the internet if it's off.
Time zone doesn't update automatically after traveling.
Confirm Location Services is enabled for time zone detection in Privacy & Security → Location Services, since automatic time zone relies on knowing your current location.
'Set time and date automatically' is greyed out and can't be toggled.
This setting can be managed by a Mobile Device Management (MDM) profile on a work or school Mac; contact your IT administrator if you need it changed.

Tips and tricks

  • Option-click the menu bar clock for a quick way to jump straight into Date & Time or Notification Center settings on some macOS versions.
  • If a specific corporate time server is required, enter its address manually in Date & Time rather than leaving the default Apple server, which some restrictive networks block.

Frequently asked questions

Why does my Mac need an internet connection to set time automatically?

It contacts a network time server to get an accurate reading; without internet access, macOS falls back to whatever time was last set, which can drift over time without correction.

Can I show seconds or the date in the menu bar clock?

Yes, but that's configured under Control Center settings' Clock options rather than in Date & Time itself, which only governs the underlying time and time zone.

Does changing time zone manually affect Calendar events?

Events created with a specific time zone attached will still display at the correct local time; only events without an assigned time zone may shift when you change zones manually.

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