this might work
net user test /time:M-F,08:00-17:00 Limits the user test to logon Monday- Friday between 8am and 5pm
net user test /time:M-F,8am-5pm The same thing can also be expressed as above using the 12 hour clock
net user test /time:M,4am-5pm;T,1pm-3pm;W-F,8:00-17:00 This shows the easiest way of setting limits that differ on multiple days.
To express Saturday and Sunday use 'sa' and 'su'.