When having configured time restricted access for some users for all services
and the time restriction is working properly with login (testes with: lightdm,
su, console login), the user can still unlock the screen being locked with
mate-screensaver out of his allowed times. The configuration used for testing
this issue in /etc/security/time.conf is:

*;*;<username>;Al0900-0901

pam_time is enabled through "common-auth" using:

account required                        pam_time.so