Yes.
You select the hours that are not allowed, on a 7 day/24 hour calendar. Any
hours not selected will be allowed.
As a child nears the end of an approved time period, they receive a
15-minute and a 1-minute notification that their time is about toexpire. If
their time ends before they log off the computer, Windows Vista suspends
their session and displays the login screen so another user can use the
computer. The child's session stays active in the background, however, so
the next time they log on, they can pick up where they left off without
losing any of their work.
Try it for yourself. Open Control Panel/User Accounts and click the Parental
Controls link in the left sidebar. Set up a "test" user and fiddle with the
settings. Log off your account and log on with the test account to see the
effects.
Open Help and Support and search for Parental Controls for the instructions.