Syncing pingboard calendar to my own calendar via Google app script

PingboardVacationSync.js

/**
 * To use:
 * 1. customize the script (see CUSTOMIZE below)
 * 2. Add this to your Google App Script dashboard https://script.google.com/a/xxx.org/
 * 3. Test run and you should see new event added to your calendar
 * 4. Add a trigger - e.g. to run every minute
 *
 * Originally from
 * https://webapps.stackexchange.com/questions/108132/how-to-automatically-forward-events-from-one-google-calendar-to-another
 *
 * API doc:
 * https://developers.google.com/apps-script/reference/calendar/calendar
 */

var GIST = 'Set by https://git.io/fNilG';
// get from https://api.slack.com/custom-integrations/legacy-tokens#
var SLACK_TOKEN = 'xoxp-xxxxxx';
// get from https://api.slack.com/methods/auth.test/test
var SLACK_USER = 'Uxxxxxx';
var NAME = 'Boris Lau';

function copyVacationEvents() {
  // company pingboard calendar
  var source = CalendarApp.getCalendarById('[email protected]'); 
  // CUSTOMIZE: my own calendar ID
  var target = CalendarApp.getCalendarById('[email protected]'); 
  var now = new Date();
  var endPeriod = new Date();
  endPeriod.setDate(endPeriod.getDate() + 30);   // 30 days from now
  
  var events = findEventFromCalendar(source, NAME, now, endPeriod);  
  for (var i = 0; i < events.length; i++) { 
    var event = events[i];
    // Since we dont see event after they finish, we need to reset status just before
    var eventEndTimeJustBefore = new Date(event.getEndTime().getTime() - 3600 * 0.5 * 1000);
    // Hack: bump to next day (normally 5pm end)
    var eventEndTimeAndAFew = new Date(event.getEndTime().getTime() + 3600 * 7 * 1000);
    
    /**
     * Setting slack status
     */
    if (event.getStartTime() <= now && now < eventEndTimeJustBefore) {
      setSlackStatus(
        // remove prefix with from title in pingboard
        event.getTitle().split(':').pop() + ' till ' + eventEndTimeAndAFew.getDate() + '/' + (eventEndTimeAndAFew.getMonth()+1) + ' (' + GIST + ')',
        ':palm_tree:'
      );
      setDND(60);
    } else if (eventEndTimeJustBefore <= now && now < eventEndTimeAndAFew) {
      setSlackStatus(
        'Back from vacation (' + GIST + ')',
        ':nerd_face:'
      );
    }

    /**
     * Copy to calendar if we did not find set event
     */
    var matchedEvents = findEventFromCalendar(target, event.getId(), now, endPeriod);
    
    if (matchedEvents.length === 0) {
      var title = event.getTitle() + ' '+ event.getId();
      if (event.isAllDayEvent()) {
        //cal.createAllDayEvent(title, event.getAllDayStartDate());
        // we want to block the date
        var eventDate = event.getAllDayStartDate();
        eventDate.setHours(0);
        while (eventDate < event.getAllDayEndDate()) {
          var nextDate = new Date(eventDate.getTime() + 60 * 60 * 24 * 1000);
          var nextDateMinusOneSec = new Date(nextDate.getTime()-1000);
          target.createEvent(title, eventDate, nextDateMinusOneSec, {
            'description': GIST
          });
          eventDate = nextDate;
        }
      }
      else {
        target.createEvent(title, event.getStartTime(), event.getEndTime(), {
            'description': GIST
          });     
      }
      Utilities.sleep(100);
    }
  }
}


function findEventFromCalendar(cal, substring, startPeriod, endPeriod) {
  var foundEvents = [];
  var events = cal.getEvents(startPeriod, endPeriod);
  for (var i = 0; i < events.length; i++) { 
    var event = events[i];
    var title = event.getTitle();
    if (title.indexOf(substring) === -1) {
      continue;
    }
    foundEvents.push(event);
  }
  return foundEvents;
}  

/**
 * https://tanaikech.github.io/2017/05/09/changing-slack-status-using-google-apps-script/
 */
function setSlackStatus(status_text, status_emoji) {
  var result = UrlFetchApp.fetch(
    'https://slack.com/api/users.profile.set',
    {
      method: 'post',
      payload: {
        token: SLACK_TOKEN,
        user: SLACK_USER,
        profile: JSON.stringify({status_text: status_text, status_emoji: status_emoji})
      },
      muteHttpExceptions: true
    }
  ).getContentText();
  var result_data = JSON.parse(result);
  if (!result_data.ok) {
    throw "Slack error: "+result;
  }
  return result_data;
}


function setDND(minutes) {
  return UrlFetchApp.fetch(
    'https://api.slack.com/api/dnd.setSnooze?token='+SLACK_TOKEN+'&num_minutes='+minutes
  ).getContentText();
}