function formatTime(ms) {
  const sec = Math.floor(ms / 1000) % 60;
  const min = Math.floor(ms / 60000) % 60;
  const hr = Math.floor(ms / 3600000);
  return `${hr}ч ${min}м ${sec}с`;
}

function countdown(targetTime) {
  const tick = () => {
    const diff = targetTime - Date.now();
    if (diff <= 0) {
      clearInterval(interval);
      console.log("Время вышло!");
    }

    else {
      console.log(formatTime(diff));
    }
  };
  tick();
  const interval = setInterval(tick, 1000);
}

countdown(Date.now() + 10000);