In this step-by-step tutorial, we’ll show you how to see how much time has elapsed since you last rebooted or started up your computer, as well as check the reboot and shutdown histories.
But why?
macOS is so efficient that you can leave your computer turned on or in sleep mode for days, weeks, and even months without needing a restart. Many users only restart their Mac when forced to do so, such as when installing a major macOS software update or when the computer lags, freezes, or apps crash.
Checking your Mac’s uptime tells you how much time has elapsed since you last rebooted or started up the machine, which could be useful when troubleshooting various issues.
For instance, knowing your reboot and shutdown histories can help pinpoint the exact date and time when you installed a major macOS software update (which requires a restart) or other updates that resulted in issues, allowing you to easily restore before that time.
A computer’s uptime can also be helpful for digital forensic purposes.
Check your Mac’s uptime
You can get this info with a Terminal command or by digging through the menus in the System Information app, with the latter giving you additional information like your Mac’s load averages.
1. Using Terminal
Open Terminal, and to get your Mac’s current uptime, type the following in Terminal and press the enter/return key:
uptime
What you should see next is a bunch of entries, each telling you how long it’s been since you last rebooted or started up your Mac, as shown in the screenshot seen below.
For those wondering about “2 users,” this is normal because aside from your own Mac user account, your computer also needs the “root” macOS account to function.
2. Using System Information
Some people are intimidated by Terminal, but there’s no need to worry, as macOS provides an alternative method for determining the Mac’s uptime.
- Click the Apple icon () from the top left corner while holding the Option key, and then choose System Information.
- Click Software in the left-hand column.
- The time since the last reboot is displayed next to ‘Time since boot’ in the right-hand section.
Tip: If your troubleshooting steps include startup key combinations for macOS’s various startup modes, and you’re unsure whether your Mac is currently in safe, verbose, recovery, or some other startup mode, look for “Boot Mode” in the System Software Overview section.
See Mac’s reboot history
Type the following in Terminal, then press the enter key to see your Mac’s reboot history:
last reboot
You should be greeted with dozens of entries that provide the exact dates and times for each reboot, whether manual or automatic (due to a system error).
With just a little tweak of the above command, you can see the shutdown history.
See Mac’s shutdown history
Conversely, this Terminal command gives you the times and dates of the last few shutdowns.
last shutdown
Again, you’ll get a list of the last couple of shutdowns, be it manual or automatic, performed by the system, along with their exact dates and times.
As someone who, until recently, worked long nights, this command was very helpful in determining how late I stayed up. I always shut down my Mac when I’m done working rather than put it to sleep. At the end of any given week, I’d simply run “last shutdown” in Terminal to see to what extent my work disrupted my sleep.
And that’s about it when it comes to checking your Mac’s uptime, girls and boys!
On a related note: