/* golf */
const toTwelveHour = time => {
    const [hr,min] = time.split(':');
    return `${hr>12?hr-12:hr==0?12:hr}:${min}${hr>12?'PM':'AM'}`;
}

/* expanded utility */
const toTwelveHour = (time) => {
  const [hour, min] = time.split(':');
  const suffix = hour > 12 ? 'PM' : 'AM';
  const hr = hour > 12 ? hour - 12 : parseInt(hour, 10);
  return `${hr === 0 ? 12 : hr}:${min}${suffix}`;
};