[rogerdraig]

as said opendns the times of day should be settable on any router via mac addresses

but in real terms the only certain parental control is
1 sitting with them
2 removing the router when you don't want it being used
3 teaching them what you expect and trusting them when old enough

personally i wouldn't allow use out of sight until you think you can trust them

at 14 i think you are at the point that either they will stick to the rules with out the extra security or they will by pass it anyway which is simple to do and easy to learn if they are set on doing so