Get hour difference between two dated

gistfile1.txt

export const getHoursDifference = (day1: string, day2: string) => {
  const dayOne = new Date(day1).getTime();
  const dayTwo = new Date(day2).getTime();
  if (Number.isNaN(dayOne) || Number.isNaN(dayTwo)) {
    throw new Error('invalid date or time format');
  }
  let hourDifference = (dayTwo - dayOne) / 1000;
  hourDifference = hourDifference / (60 * 60);
  return hourDifference;
};

//Format 12 hours time to 24 hours
export function formatDate(date: any, time: any) {
  let day = date.split('T');
  day = day[0];
  const format = time.match(/[a-zA-Z]+/);
  let formatedDate: string;
  if (format) {
    // ['pm', 'PM', 'am', 'AM'].includes(format[0]);

    const hour = Number(time.match(/^(\d+)/)[1]);
    const minute = time.match(/:(\d+)/)[1];
    if (format[0] == 'pm' || format[0] == 'PM') {
      if (hour < 12) {
        formatedDate = `${day}T${hour + 12}:${minute}:00.000Z`;
      }
    }
    if (format[0] == 'am' || format[0] == 'AM') {
      if (hour < 12) {
        if (hour < 10) {
          formatedDate = `${day}T${'0' + hour}:${minute}:00.000Z`;
        } else {
          formatedDate = `${day}T${hour}:${minute}:00.000Z`;
        }
      }
      if (hour == 12) {
        formatedDate = `${day}T${hour - 12}:${minute}:00.000Z`;
      }
    }
    return formatedDate!;
  } else {
    return `${day}T${time}:00.000Z`;
  }
}