Move(archive) emails from one label to another automatically after X days. Useful for reducing Newsletter FOMO and pile-up.

README.md

Gmail Label Modifier: Automatically move emails b/w labels after X days. One time setup!

Follow the steps in this blogpost. I basically copied and modified some code from 2-3 sources, all are mentioned in the blogpost. Reply below or DM on twitter if this was helpful :)

gmail label modifier.js

// The name of the Gmail Label(s) that are to be moved to an Archiving Label (which you've already made earlier).
//Note: I need to do a small modification. For now, add just 1 label to LABELS_TO_DELETE like shown below
var LABELS_TO_DELETE = [
  "Newsletters"
];

var ARCHIVE_LABEL= "Old Newsletters"; 
var TRIGGER_NAME = "dailyDeleteGmail";

// Purge messages in the above label automatically after how many days?
var DELETE_AFTER_DAYS = "7";

//Add your timezone
var TIMEZONE = "IST"; 

// Maximum number of threads to process per run
var PAGE_SIZE = 150;

// If number of threads exceeds page size, resume job after X mins 
// (max execution time is 6 mins. info regarding other quota limits in Google AppScript docs)
var RESUME_FREQUENCY = 10;



// IMPLEMENTATION


function Initialize() {
  return;
}

function Install() {

  // First run 2 mins after install
  ScriptApp.newTrigger(TRIGGER_NAME)
           .timeBased()
           .at(new Date((new Date()).getTime() + 1000*60*2))
           .create();
  
  // Run daily there after
  ScriptApp.newTrigger(TRIGGER_NAME)
           .timeBased().everyDays(1).create();

}

function Uninstall() {
  
  var triggers = ScriptApp.getProjectTriggers();
  for (var i=0; i<triggers.length; i++) {
    ScriptApp.deleteTrigger(triggers[i]);
  }
  
}

function dailyDeleteGmail() {

  var age = new Date();  
  age.setDate(age.getDate() - DELETE_AFTER_DAYS);    
  
  var purge  = Utilities.formatDate(age, TIMEZONE, "yyyy-MM-dd");
  var search = "(label:" + LABELS_TO_DELETE.join(" OR label:") + ") before:" + purge;
  Logger.log("PURGE: " + purge);
  Logger.log("SEARCH: " + search);
  
  try {
    
    var threads = GmailApp.search(search, 0, PAGE_SIZE);
    
    // Resume again in 10 minutes
    if (threads.length == PAGE_SIZE) {
      Logger.log("Scheduling follow up job...");
      ScriptApp.newTrigger(TRIGGER_NAME)
               .timeBased()
               .at(new Date((new Date()).getTime() + 1000*60*RESUME_FREQUENCY))
               .create();
    }
    
    // MOVE threads which meet age criteria from LABELS_TO_DELETE to ARCHIVE_LABEL.
    Logger.log("Processing " + threads.length + " threads...");
    for (var i=0; i<threads.length; i++) {
      var label1 = GmailApp.getUserLabelByName(LABELS_TO_DELETE[0]); // FROM
      var label2 = GmailApp.getUserLabelByName(ARCHIVE_LABEL); // TO
      var thread = threads[i];
      
      if (thread.getLastMessageDate() < age) {
        thread.addLabel(label2).removeLabel(label1);
      }
    }
    
  } catch (e) {}
  
}