Get Exact Boot and Uptime on Ubuntu from the Command Line

Want to know exactly when you last booted your Ubuntu machine, or how long it’s been since you last did?
Probably not —but I’m going to show you how anyway.
Detailed boot information can be useful when troubleshooting issues, especially useful if your think your system has rebooted without you asking it to, or you’re encountering issues with scheduling, power, and so on.
While there is a myriad of ways to get and display these snippets of data, we’re going to focus on ones that Ubuntu natively supports out of the box. Many great (great) tools can be installed to provide more information, e.g., procinfo.

Get Exact System Boot Time on Ubuntu

To get the exact time and date that your machine was booted enter the following command in the Terminal:

uptime -s

The results will look something like: 2016-10-31 14:57.

Get Uptime on Ubuntu

If you’re only want to know how long your Ubuntu machine has been powered on, use the simple uptime command instead:

uptime -p

The results will look something like:15:22  up 10 days, 23 mins, 2 users, load averages: 1.41 1.42 1.35. Ignore the information on the end (unless it’s of use).
Simple!