convertTime.ts

/**
 * @param time - The time in 24 hours format
 * @returns The time in 12 hours format
 */
export function convertTime24to12(time: string): string {
  const [hours, minutes]: number[] = time.split(':').map(Number);
  const meridiem: 'PM' | 'AM' = hours >= 12 ? 'PM' : 'AM';
  return `${hours % 12 || 12}:${minutes
    .toString()
    .padStart(2, '0')} ${meridiem}`;
}

/**
 *
 * @param time - The time in 12 hours format
 * @returns The time in 24 hours format
 */
export function convertTime12to24(time: string): string {
  let [hours, minutes]: number[] = time.split(' ')[0].split(':').map(Number);
  const meridiem: string = time.split(' ')[1];

  if (meridiem.toUpperCase() === 'PM' && hours < 12) hours += 12;
  else if (meridiem.toUpperCase() === 'AM' && hours === 12) hours = 0;

  return `${String(hours).padStart(2, '0')}:${String(minutes).padStart(
    2,
    '0',
  )}`;
}