title: Why is Google scripts requiring re-authentication every few hours?
body: <p>I have one script file running on a google spreadsheet with 7 custom functions.  One is triggered  via onOpen, 4 are via onEdit, and 2 via custom menu items.  When done editing the script, I do a final save and debug on one of the functions to make sure that the script has been "authenticated".  Reopening the associated spreadsheet works fine for a few hours (both for me and for others who have shared access).  At some point a few hours later, the onOpen script throws an authentication error:</p>
  
  <p>"Authorization is required to perform that action" </p>
  
  <p>and the other functions don't work until I log back in and reauthenticate.</p>
  
  <p>Why would this happen?  I thought re-authentication would only be needed if I make a change to the script.  Is there any way i can debug this so that it stays 'authenticated'?  I need this to work 24/7.</p>
  
  <p>For reference, the various functions hide rows, copy/update cells, delete cell contents, add menu items, calculate dates, etc but nothing too fancy.  One function, currently commented out has a UrlFetchApp line that will pull JSON data from another site.</p>
  
  <p>Thanks,</p>
  
  <p>-BW </p>