Set What Hours User Can Login

You can use the 'Net User' command to configure the day and the time when a user can log on to a computer. For example, you could permit a user named Fred to only log on to a computer between the hours of 10am and 3pm Monday-Wednesday.

• From the Run... command, type "CMD" and press enter,
• At the MS-DOS console, type "net user fred /time:M-W, 10:00-15:00"

For more information NET USER command see this MSKB (Microsoft Knowledge Base Article).

Note: If the user is already logged into the computer during the restricted time, they're not prevented from using the computer.