Incorrect Time on Mac: Fixing Clock Synchronization Issues

What the NO_NTP_SYNC Error Means

The system reports that it cannot synchronize the system clock with a reference server. In the UI, this appears as a warning in the menu bar, incorrect dates in notifications, or "Failed to synchronize date and time" messages in the Console log. This error blocks services that rely on accurate timestamps: TLS encryption, corporate network authentication, license validation, and automatic update downloads.

Common Causes

Clock desynchronization rarely occurs on its own. It is typically triggered by the following factors:

1. Disabled automatic synchronization. Accidentally toggling the switch in settings or running a system optimizer.
2. Blocked NTP traffic. A corporate firewall, restrictive VPN, or router settings blocking UDP port 123, which the synchronization protocol uses.
3. timed daemon crash. An internal error in the macOS service responsible for background clock updates. The daemon stops responding to kernel requests.
4. NVRAM corruption. On Intel Macs, the NVRAM battery preserves clock settings. When it degrades, settings reset upon complete power loss.

Troubleshooting Steps

Method 1: Restart the Synchronization Service via Settings

This is the safest approach and resolves the issue in 80% of cases. macOS often hangs when attempting to connect to the server, and simply toggling the switch resets the stuck process.

1. Open the Apple menu () in the top-left corner and select System Settings.
2. Navigate to General → Date & Time.
3. Click the lock icon 🔒 in the bottom-right corner and enter your administrator password if the settings are locked.
4. Turn off the Set date and time automatically toggle, wait 10 seconds, and turn it back on.
5. Wait for a checkmark to appear next to the synchronization server.

💡 Tip: If the interface becomes unresponsive, completely quit the Settings window using Cmd + Q and reopen it. This reloads the module's GUI without affecting system daemons.

Method 2: Manually Change the Time Zone

Sometimes the clock shows the correct UTC time but displays the wrong local time due to an incorrect region setting. While this isn't a synchronization error, users often perceive it as one.

1. In the Date & Time section, locate the Time Zone setting.
2. Ensure the Set time zone automatically using your current location toggle is enabled.
3. If automatic selection fails, disable the toggle and click the dropdown menu. Manually enter your city's name.
4. Press Enter and check if the time in the menu bar updates correctly.

Method 3: Force Synchronization via Terminal

When the GUI fails to relay commands to the daemon, use the sntp utility. It contacts Apple's server directly and updates the system clock, bypassing the standard cache.

1. Open the Terminal app via Spotlight (Cmd + Space → type Terminal → Enter).
2. Paste the following command and press Enter:

sudo sntp -sS time.apple.com

3. Enter your administrator password (characters will not be displayed on screen) and press Enter to confirm.
4. Wait for the output showing the offset and delay. If the command completes without errors, the time will be updated instantly.

⚠️ Important: You must run this command with sudo privileges, as changing the system time requires kernel-level access in macOS. Without the prefix, the utility will return an Operation not permitted error.

Method 4: Restart the timed Daemon and Reset NVRAM

If the issue returns after every reboot, the timed background process is likely corrupted, or the hardware time zone settings have been reset.

1. Force restart the service in Terminal:

sudo launchctl kickstart -k system/com.apple.timed

This command terminates the stuck process and restarts it, pulling a fresh configuration from /System/Library/LaunchDaemons/.

2. To fully reset the hardware timers:
   • Apple Silicon: Simply restart your Mac. NVRAM on these chips does not require manual initialization.
   • Intel: Shut down the computer. Turn it on and immediately press and hold Option + Command + P + R for about 20 seconds, until you hear the startup chime a second time or see the Apple logo appear and disappear again.

After completing these steps, verify the synchronization status in Settings. The error should be resolved.

Prevention

To keep your Mac's clock accurate and prevent certificate conflicts, follow these best practices:

• Avoid third-party system "cleaners" that disable background daemons to save battery. This disrupts timed and ntpd operations.
• When connecting to public Wi-Fi or corporate networks, ensure your firewall isn't blocking UDP port 123. Allowing outbound traffic on this protocol is sufficient for synchronization.
• If you travel frequently and change regions, keep the automatic time zone detection enabled. Manually changing time zones while crossing borders increases the risk of desynchronization from global servers.
• On older Macs (pre-2015 models), monitor the condition of the logic board battery. Replacing the CR2032 battery on the NVRAM board will resolve the issue of the clock constantly resetting when unplugged.