Extraer fechas de /etc/shadow

chage -l <username>

Salida de ejemplo:

Last password change                                    : Dec 17, 2015
Password expires                                        : Mar 16, 2016
Password inactive                                       : never
Account expires                                         : never
Minimum number of days between password change          : 7
Maximum number of days between password change          : 90
Number of days of warning before password expires       : 14

for n in $(sudo cat /etc/shadow | awk '{FS=":";print $3}'); do date -d "01/01/1970 +${n}days" +%F; done 

Para evitar el premio-uso-inútil-del-gato:

for n in $(sudo awk '{FS=":";print $3}' /etc/shadow); do date -d "01/01/1970 +${n}days" +%F; done 

informar el estado de la contraseña en la cuenta nombrada passwd -S username

for user in $(cut -d: -f1 /etc/passwd); do sudo passwd -S $user; done