Sometimes Apple needs your Mac to know exact what time is it. Most leave Macs set to the default setting where the time is set via one network server which keeps it updated to the other. However, you may have turned off that feature, resetting the clock manually to check something, or preventing a date-based expiration, or having a hardware problem causing an error. (Some Macs include long-life battery life designed to keep the clock ticking and preserve other settings.)
If your Mac does not know the correct time, you may have problems syncing Apple ID and iCloud, unable to log in to the App Store or download updates, let your Mac say it can not connect to servers when you are in macOS Recovery, or if the process fails to recover a lost FileVault key once you have allowed it to be stored in your iCloud account.
If your Mac is running, you can use the Date & Time setting pane to check the time. You can activate automatic date / time setting if it is off, or if it is on and incorrect, deactivate it and set the clock manually. (If you disconnect and reconnect your Mac desktop and the clock is incorrect, you will almost certainly need to replace the battery with the internal settings.)
When you recover your Mac or try to access the FileVault recovery key with your Apple ID, things can get harder.
The goal is to bring up Terminal, where you enter one of the following two commands. Terminal is an option in macOS Recovery in the Tools menu.
If you cannot get recovery mode to appear at all or retrieve Terminal, create a bootable installer with a USB memory stick or other external drive. (We have instructions on how to create a bootable installer for Big Sur and Catalina.) When starting from that drive, you should be able to access Terminal by selecting the Recovery partition – this may require you to hold down Option at startup for to select an individual disk to be displayed.
In the terminal you can try one:
ntpdate -u time.apple.com
This contacts Apple’s time server directly and sets the clock. If you are unable to establish an Internet connection or it does not work, try using
date command, followed by month, day, hour, minute, and year (the last two digits), with zeros that fill single-digit entries. For example, March 12, 2020 at 09:30 looks like this
In some cases, you may need to restart before date and time recognition is recognized and let you continue.
If you cannot access the Terminal app, you will need to find a remote drive for your Mac with macOS installed (or which you can install macOS from another Mac), and you can then boot from it. You can use the settings pane to set the date and time or use Terminal once it has started up in macOS.
This Mac 911 article is an answer to a question from Macworld reader Paul.
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