format date

formatDate.js

const MONTH_NAMES = [
  'January',
  'February',
  'March',
  'April',
  'May',
  'June',
  'July',
  'August',
  'September',
  'October',
  'November',
  'December',
];

// input date object
// July 15, 2020 at 1:30PM EST
function formatDate(dateObject) {
  const monthNumber = dateObject.getMonth();
  const month = MONTH_NAMES[monthNumber];

  const dayDate = dateObject.getDate();

  const fullYear = dateObject.getFullYear();

  const localHours = dateObject.getHours();

  const localMinutes = `${(dateObject.getMinutes() < 10 ? '0' : '')}${dateObject.getMinutes()}`;

  const localTime = `${localHours % 12 || 12}:${localMinutes}${localHours >= 12 ? 'PM' : 'AM'}`;

  // get local timezone abbreviation
  // String(String(rightNow).split("(")[1]).split(")")[0])
  // somewhat less reliable for other timezones
  // via https://stackoverflow.com/questions/1954397/detect-timezone-abbreviation-using-javascript
  const timezoneAbbreviation = dateObject.toLocaleTimeString(undefined, { timeZoneName: 'short' }).split(' ')[2];

  return `${month} ${dayDate}, ${fullYear} at ${localTime} ${timezoneAbbreviation}`;
}

export default formatDate;