How to check the installation date of Linux

To find out when Linux was installed on your host, there isn’t a default command, but here are some useful tricks:

Using rpm to check installation time of basesystem (Preferred Method):

rpm -q basesystem --qf '%{installtime:date}\n'

Using ls and awk commands:

   ls -alct / | tail -1 | awk '{print $6, $7, $8}'

Using the stat command on root directory: In this method take attention to the last field ‘birth’

stat --format=%w /

Note: The “birth” field might display “-“.