SHELL

get date installation os

Linux:
fs=$(df / | tail -1 | cut -f1 -d' ') && tune2fs -l $fs | grep 'Filesystem created'
stat / | grep -E "(Birth|Creación)"

Windows:
systeminfo | find /i "Fecha"

os installation date

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