timer.ts

const SECOND = 1000;
const MINUTE = SECOND * 60;
const HOUR = MINUTE * 60;
const DAY = HOUR * 24;

const TIME = {
  second: SECOND,
  minute: MINUTE,
  hour: HOUR,
  day: DAY,
};

const formatNumber = (n: number) => n < 10 ? `0${n}` : n;

function getTimerData(next: number) {
  const days = Math.floor(next / TIME.day);
  const hours = Math.floor(next / TIME.hour - days * 24);
  const minutes = Math.floor(next / TIME.minute - days * 24 * 60 - hours * 60);
  const seconds = Math.floor(next / TIME.second - minutes * 60 - days * 24 * 60 * 60 - hours * 60 * 60);

  return {
    days,
    hours: formatNumber(hours),
    minutes: formatNumber(minutes),
    seconds: formatNumber(seconds),
  };
}