title: TFS 2015 Build definition - override Build number with variables
body: <p>We use a nice $(date:yyyy.MM.dd)$(rev:.r) build number format in our day-to-day agile sprints. However, the release must be numbered with a simpler 1.0.0.rev schema.</p>
  
  <p>Ideally, I would like to give the build number as a variable, which would be automatically expanded in the "queue build" dialog, where it would be possible to be overriden. How can it be done?</p>
  
  <p>I tried moving the $(date:yyyy.MM.dd)$(rev:.r) format to a variable, and use that variable in the general tab, and got error 400.</p>