无法从Google Sheets同步日程至Google Calendar，代码报错求助

我尝试将Google Sheets中的日程同步至Google Calendar以避免手动添加操作，编写了一段Google Apps Script代码但运行报错。以下是报错信息截图、表格样式截图及代码，请求协助排查问题：

function scheduleShifts() {
var spreadsheet = SpreadsheetApp.getActiveSheet();
var calendar_ID = spreadsheet.getRange("A1").getValue();
var eventCal = CalendarApp.getCalendarById(calendar_ID);

var events = spreadsheet.getRange("H2:I996").getValues();

for (x=0; x<events.length; x++) {

  var schedule = events[x];

  var startTime = schedule[7];
  var endTime = schedule[8];
  var name = schedule[2];
  var address = schedule [3];
  var phone = schedule [4];
  var description = schedule[5];
  var comments = schedule[6];

  eventCal.createEvent(address, startTime, endTime);

  }
  
}

function onOpen() {

  var ui = SpreadsheetApp.getUi();
  ui.createMenu('Sync to Calendar')
      .addItem('Schedule shifts now', 'scheduleShifts')
      .addToUi();
}

内容的提问来源于stack exchange，提问作者Joe Gonzalez