function attachEventsListeners() {
     Array.from(document.querySelectorAll('[type="button"]')).forEach(b => b.addEventListener('click', onClick));

     const buttons = {
         daysBtn: (i) => Number(i) * 24 * 60 * 60,
         hoursBtn: (i) => Number(i) * 60 * 60,
         minutesBtn: (i) => Number(i) * 60,
         secondsBtn: (i) => Number(i),
     }


     function onClick(e) {
         const input = e.target.previousElementSibling.value;
         const seconds = buttons[e.target.id](input);

         const minutes = seconds / 60;
         const hours = minutes / 60;
         const days = hours / 24;

         document.getElementById('days').value = days;
         document.getElementById('hours').value = hours;
         document.getElementById('minutes').value = minutes;
         document.getElementById('seconds').value = seconds;
     }
 }