Converts a Javascript UTC date string into the proper format for ICS calendar files for DTSTAMP, DTSTART and DTEND

toICSDateFormat.js

/**
 * Converts a UTC date into the proper format for ICS calendar files for DTSTAMP, DTSTART and DTEND
 * @param {String} isoDateString, e.g. new Date().toISOString()
 * @returns {String} formatted as UTC date for ICS files, e.g. 20220511T170000Z
 */

const toICSDateFormat = (isoDateString) => {
  const dateArray = isoDateString.split("T");
  const day = dateArray[0].replace(/-/g, "");
  const time = dateArray[1].replace(/[a-zA-Z]+/g, "").split(":");
  const ics = `${day}T${getDigits(time[0])}${getDigits(time[1])}${getDigits(
    time[2],
  )}Z`;
  return ics;
};

/**
 *
 * @param {String} timeString, e.g. '2.19'
 * @returns {String} 2 digit string, e.g. '02'
 */
const getDigits = (timeString) => {
  let digits = String(Math.round(parseInt(timeString, 10)));
  if (digits.length === 1) digits = `0${digits}`;
  return digits;
};