Gmail Scheduler

Code.gs

function installScript() {
  
  // Makes sure that only 1 scheduler is installed
  uninstallScript();
  
  // Trigger every 1 hour.
  ScriptApp.newTrigger('gmailScheduler')
      .timeBased()
      .everyHours(1)
      .create();
}

function uninstallScript() {
  var allTriggers = ScriptApp.getProjectTriggers();
  for (var i = 0; i < allTriggers.length; i++) {
    Logger.log(allTriggers[i]);
    
    // If the current trigger is the correct one, delete it.
    if (allTriggers[i].getHandlerFunction() === "gmailScheduler") {
      ScriptApp.deleteTrigger(allTriggers[i]);
    }
  }
  
}


// this function runs every 1 hour
function gmailScheduler() {
 
    /* Clear the current sheet */
    var sheet = SpreadsheetApp.getActiveSheet();
    sheet.getRange(2, 1, sheet.getLastRow() + 1, 5).clearContent();
 
    /* Delete all existing triggers */
    var triggers = ScriptApp.getProjectTriggers();
    for (var i = 0; i < triggers.length; i++) {
        if (triggers[i].getHandlerFunction() === "sendMails") {
            ScriptApp.deleteTrigger(triggers[i]);
        }
    }
 
    /* Import Gmail Draft Messages into the Spreadsheet */
    
    var drafts = GmailApp.getDraftMessages();
    if (drafts.length > 0) {
        var rows = [];
        for (var i = 0; i < drafts.length; i++) {
            if (drafts[i].getTo() !== "") {
                var scheduled=null;
                var subject = drafts[i].getSubject();
                var regExp = new RegExp("^@(.*)@[ ]*(.*)", "gi");
                var parsed = regExp.exec(subject);
                if(parsed!=null) {
                   scheduled = parsed[1];
                   subject = parsed[2]
                }
                /*
                //tries to analyse commons expressions: tomorrow, etc.
                if(scheduled==="tomorrow") {
                  //tomorrow is at 9:00 of the next day
                  scheduled=new Date(new Date(tomorrow.setHours(9)).setMinutes(0)).toISOString().substring(0, 16).replace('T',' ');
                  //xxxxx
                }*/
                
              
                //use the spreadsheet to parse the format of the date
                rows.push([drafts[i].getId(), drafts[i].getTo(), subject, scheduled,""]);
                
             //scheduledLabel.addToThread(drafts[i].getThread());
            }
        }
        sheet.getRange(2, 1, rows.length, 5).setValues(rows);
    }
  
    setSchedule();
}
 
/* Create time-driven triggers based on Gmail send schedule */
function setSchedule() {
    var sheet = SpreadsheetApp.getActiveSheet();
    var data = sheet.getDataRange().getValues();
    var time = new Date().getTime();
    var code = [];
 
  
    /* creates label 'Scheduled' in gmail */
    var scheduledLabel = GmailApp.getUserLabelByName('Scheduled'); 
    if( scheduledLabel == null ) {
      scheduledLabel = GmailApp.createLabel('Scheduled');
    }
    /* */
  
    for (var row in data) {
      if (row == 0) {
        continue;
      }
      
      var schedule = data[row][3];
      if (schedule == undefined || schedule === "" || !(schedule instanceof Date) ) {
        code.push("Not Scheduled");  
        scheduledLabel.removeFromThread(GmailApp.getMessageById(data[row][0]).getThread())
        continue;
      }
      
      if (schedule.getTime() > time) {
        ScriptApp.newTrigger("sendMails")
        .timeBased()
        .at(schedule)
        .inTimezone(SpreadsheetApp.getActiveSpreadsheet().getSpreadsheetTimeZone())
        .create();
        code.push("Scheduled");
        scheduledLabel.addToThread(GmailApp.getMessageById(data[row][0]).getThread())

      } else {
        code.push("Date is in the past");
        scheduledLabel.removeFromThread(GmailApp.getMessageById(data[row][0]).getThread())

      }
    }
    
    for (var i = 0; i < code.length; i++) {
        sheet.getRange("E" + (i + 2)).setValue(code[i]);
    }
}
 
 
function sendMails() {
    var sheet = SpreadsheetApp.getActiveSheet();
    var data = sheet.getDataRange().getValues();
    var time = new Date().getTime();
 
    for (var row = 1; row < data.length; row++) {
        if (data[row][4] == "Scheduled") {
            var schedule = data[row][3];
            if ((schedule != "") && (schedule.getTime() <= time)) {
                var message = GmailApp.getMessageById(data[row][0]);
                
                var subject = message.getSubject();
                var regExp = new RegExp("^@(.*)@[ ]*(.*)", "gi");
                var parsed = regExp.exec(subject);
                if(parsed!=null) {
                   subject = parsed[2]
                }
              
                // there is no API for sending directly the email
                //so, I send a copy of it
                var body = message.getBody();
                var options = {
                    cc: message.getCc(),
                    bcc: message.getBcc(),
                    htmlBody: body,
                    replyTo: message.getReplyTo(),
                    attachments: message.getAttachments()
                }
  
                GmailApp.sendEmail(message.getTo(), subject, body, options);
                message.moveToTrash();
                
                sheet.getRange("E" + (row + 1)).setValue("Delivered");
            }
        }
    }
}

Hello, i tried a lot, but i always get Not Scheduled. Once i got Date is in the past. What should i do?