My mum wanted to have a way to stop my brother playing runescape in the week   so I made this bash script that runs at boot. Just put it in /etc/init.d then update your init Using apt-get is kind of crude maybe be swapping out symlinks would be better.

#!/bin/bash
Day=`date ‘+%u’`
echo “$Day”

if [ “$Day” = “6” ]; then
echo its the weekend
apt-get install -y sun-java6-plugin
fi

if [ “$Day” = “7” ]; then
echo its the weekend
apt-get install -y sun-java6-plugin
fi

if [ “$Day” != “7” ] && [ “$Day” != “6” ]; then
echo its not the weekend
apt-get remove sun-java6-plugin
fi