How to check Linux last reboot time?

We can use the who command with the -b flag to check Linux last reboot date and time. Root privileges are not necessary to perform this check.

$ who -b
system boot  2020-08-29 06:39

To check the date and time of all previous Linux system reboots, we can use the last reboot command. This gets the information from the /var/log/wtmp file.

$ last reboot
reboot   system boot  4.15.0-117-gener Mon Sep 14 16:54   still running
reboot   system boot  4.15.0-117-gener Mon Sep 14 16:51 - 16:54  (00:02)
reboot   system boot  4.15.0-117-gener Mon Sep 14 16:49 - 16:51  (00:01)

wtmp begins Mon Sep  7 04:31:42 2020

Learn more Linux commands.