gmail auto reply schedule

auto_reply_holiday.js

function autoReply() {
  var scheduled_date = [
    '2016-12-19', '2016-12-20',
  ];
  var auto_reply = "I am out of office. Your email will not seen until Monday morning.";

  var now = new Date();
  var today = now.toISOString().slice(0, 10); // today format: '2017-01-01'
  
  var label = GmailApp.getUserLabelByName('auto-replyed') || GmailApp.createLabel('auto-replyed');
    
  // today is the scheduled date
  if (scheduled_date.indexOf(today) >= 0) { 
    // get all email inbox, unread, without label auto-replyed
    var threads = GmailApp.search('is:unread is:inbox -{label:auto-replyed}');
    for (var i = 0; i < threads.length; i++) {
      var thread = threads[i]
      // reply the email and add auto-replyed label
      thread.reply(auto_reply);
      thread.addLabel(label);
    }
  }
}

auto_reply_off.js

function autoReply() {
  var auto_reply = "Thank you for your email. Your message is important to us and we will respond as soon as possible. \n\
Client Service Desk \n\
Monday - Friday: 8:00 am - 5:00 pm CT";

  var now = new Date();
  
  var label_checked = GmailApp.getUserLabelByName('auto-reply-checked') || GmailApp.createLabel('auto-reply-checked');
  var label_replied = GmailApp.getUserLabelByName('auto-replied') || GmailApp.createLabel('auto-replied');
    
  // get all email inbox, unread, without label auto-reply-checked
  var threads = GmailApp.search('is:unread is:inbox -{label:auto-reply-checked}');
  for (var i = 0; i < threads.length; i++) {
    var thread = threads[i]
    var thread_date = thread.getLastMessageDate();

    var weekday = thread_date.getDay();
    var hour = thread_date.getHours();
    var is_weekend = (weekday == 0 || weekday > 5);
    var is_after_work = (hour >= 12 || hour < 8);
    
    if ( is_weekend || is_after_work ) {
      thread.reply(auto_reply);
      thread.addLabel(label_replied);
    }
    thread.addLabel(label_checked);
  }
}