Archive Old Email Messages in Gmail Automatically

The Google Script will archive all email threads in a specific Gmail label that have been inactive for more than a week. It takes the date of the last message in a thread and if it is older than a week, the thread is archived. The current labels is removed as well.

function ArchiveOldEmails(gmailLabelName){
  
  var gmailLabel = GmailApp.getUserLabelByName(gmailLabelName);
  
  var ONE_WEEK = 60 * 60 * 24 * 7 * 1000;
  
  var threads = label.getThreads();
  var now     = new Date();
  
  for (var j=0; j<threads.length; j++) {
    if (now - threads[j].getLastMessageDate() > ONE_WEEK){
      threads[j].moveToArchive().removeLabel(gmailLabel);
    }
  }
  
}