title: How to schedule jenkins to start every day between 6PM to 7AM and on frieday and saterday run every 30 minutes
body: <p>I am trying to schedule a jenkins build with the following: 
  start every day between 6PM to 7AM and on Friday and Saturday run every 30 minutes... but it seems for some reason a little bit hard. 
  Any help will be appreciates. </p>