title: How to run a PHP script automatically in every month
body: <p>I have the php project for user can register and buy the hours to listen music or video, the not used of 50% hours have to rollover to next month, I wanted to automate this process when user complete one month I have to check their usage and process the rollover using php. I have following user details on DB, Signed-up date with time and usage and hours they purchased and used hours. I want to do it once in a month for each customer. </p>
  
  <p>Is it possible using cron jobs? I don't have any idea to do this.</p>