const result = calendareventsupdate calendarId primary auth oauth2Client eventId googleevents resource updatedEvent ; cons

To move the code into a promise, you can use the Promise.all() method to handle multiple asynchronous requests. Here's an example:

const updateGoogleCalendar = () => {
  return new Promise((resolve, reject) => {
    calendar.events.update(
      {
        calendarId: 'primary',
        auth: oauth2Client,
        eventId: googleevents,
        resource: updatedEvent,
      },
      (err, result) => {
        if (err) {
          reject(err);
        } else {
          resolve(result);
        }
      }
    );
  });
};

const updateOutlookCalendar = () => {
  return new Promise((resolve, reject) => {
    const start = {
      dateTime: new Date(start_date),
      timeZone: 'Asia/Kolkata'
    };

    const end = {
      dateTime: new Date(end_date),
      timeZone: 'Asia/Kolkata'
    };

    // make outlook calendar update request here

    // resolve with response from outlook calendar API
    resolve(response);
  });
};

Promise.all([updateGoogleCalendar(), updateOutlookCalendar()])
  .then((results) => {
    console.log('Google calendar update result:', results[0]);
    console.log('Outlook calendar update result:', results[1]);
  })
  .catch((err) => {
    console.error('Calendar update error:', err);
  });

In this example, updateGoogleCalendar() and updateOutlookCalendar() are both wrapped in promises. The Promise.all() method is then used to execute both promises simultaneously and wait for both to resolve or reject. Once both promises have resolved, the then() method is called, which logs the results of both calendar updates. If either promise rejects, the catch() method is called, which logs the error.