Im currently working on a simple internal add-on for google calendar. When we click a event we will choose a option from a dropdown and click a button. When that happens, take the selected item with its corresponding attributes (working) and the events start and end- time. I cannot for the love of me get the time to work. What am I missing?

For now the logic is not there i just simply want to see the start and end times in the Log.

When this runs, and a item is selected, and we press the button we will in the log get the following:

Apr 23, 2025, 8:40:24 AM Info Selected customer ID: 1337 Apr 23, 2025, 8:40:24 AM Info Event start time: Invalid Date Apr 23, 2025, 8:40:24 AM Info Event end time: Invalid Date

This is the script:

/**
 * Callback for opening a calendar event.
 * @param {Object} e The event object for the open callback.
 * @return {CardService.Card} The card to show to the user.
 */
function onCalendarEventOpen(e) {
  var cardBuilder = CardService.newCardBuilder();
  var customerData = getCustomersFromApi();

  var selectionInput = CardService.newSelectionInput()
      .setType(CardService.SelectionInputType.DROPDOWN)
      .setFieldName("dropdown_field")
      .setTitle("Select a customer");

  customerData.forEach(function(customer) {
    selectionInput.addItem(customer.name, customer.id, false);
  });

  var startTime = "";
  var endTime = "";

  // SAFELY extract start and end time strings from calendar event
  if (e && e.calendarEvent) {
    var event = e.calendarEvent;
    if (event.getStartTime && event.getEndTime) {
      startTime = event.getStartTime().toISOString();
      endTime = event.getEndTime().toISOString();
    }
  }

  var action = CardService.newAction()
    .setFunctionName("onTidsraporteraClick")
    .setParameters({
      startTime: startTime,
      endTime: endTime
    });

  var button = CardService.newTextButton()
      .setText("Tidsraportera")
      .setOnClickAction(action);

  var section = CardService.newCardSection()
      .addWidget(selectionInput)
      .addWidget(button);

  return cardBuilder.addSection(section).build();
}

/**
 * Callback for when the "Tidsraportera" button is clicked.
 * Logs the selected customer and the calendar event start/end times.
 * @param {Object} e The event object containing form inputs and parameters.
 * @return {CardService.ActionResponse}
 */
function onTidsraporteraClick(e) {
  try {
    var selectedCustomerId = e.commonEventObject.formInputs["dropdown_field"].stringInputs.value[0];
    Logger.log("Selected customer ID: " + selectedCustomerId);

    var startTime = new Date(e.parameters.startTime);
    var endTime = new Date(e.parameters.endTime);

    Logger.log("Event start time: " + startTime);
    Logger.log("Event end time: " + endTime);
  } catch (error) {
    Logger.log("Error in onTidsraporteraClick: " + error);
  }

  return CardService.newActionResponseBuilder()
    .setNotification(CardService.newNotification()
      .setText("Customer: " + selectedCustomerId + "\nStart: " + startTime + "\nEnd: " + endTime))
    .build();
}

This is a part of the appscript.json:

{
  "timeZone": "Europe/Berlin",
  "runtimeVersion": "V8",
  "oauthScopes": [
    "https://www.googleapis.com/auth/calendar.addons.execute",
    "https://www.googleapis.com/auth/script.locale",
    "https://www.googleapis.com/auth/calendar.readonly",
    "https://www.googleapis.com/auth/calendar",
    "https://www.google.com/calendar/feeds",
    "https://www.googleapis.com/auth/script.external_request"
  ],

Ive experimented with grabing it as a date, a string and then passing it to the onClick to then convert it back to Date. For this version we are getting Invalid date, but before that mostly I was getting Undefined so there is something wrong when i try to grab the events time.