Respostas:
Abra um terminal e digite o comando: last
chris@chriss-mbp-2:~/Documents/dev/git/$ last
chris ttys005 Sun Dec 22 01:51 - 02:57 (01:06)
chris ttys005 Sun Dec 22 01:50 - 01:51 (00:00)
chris ttys004 Sat Dec 21 13:32 - 19:53 (1+06:20)
chris ttys003 Sat Dec 21 13:32 still logged in
chris ttys002 Sat Dec 21 13:32 still logged in
chris ttys001 Sat Dec 21 13:32 still logged in
chris ttys000 Sat Dec 21 13:32 still logged in
chris console Sat Dec 21 13:32 still logged in
reboot ~ Sat Dec 21 13:32
shutdown ~ Sat Dec 21 13:32
Mais detalhes sobre o último podem ser encontrados nas páginas de manual aqui .