This bash script runs every minute on my home server, keeps me from staying up too late.

enforcer.sh

#!/bin/bash                                                                       

# Usage: enforcer.sh                                                              

curfew_active=`curl -s http://superego.herokuapp.com/api/v1/curfew/is_active`
curfew=`curl -s http://superego.herokuapp.com/api/v1/curfew/compute`
now=`date`

if [ $curfew_active == 'true' ]
then
  echo "$now: GO TO SLEEP" >> /tmp/enforcer.log
  sudo killall -u david -m 'Chrome|Hearthstone|SC2|Safari|Firefox'
else
  echo "$now: CARRY ON until $curfew" >> /tmp/enforcer.log
fi