live_exam

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<!DOCTYPE html>
<html>
<head>
  <style> #hiddenButton { display: none;  } </style>
</head>
<body>
  
  <div id="countdown"></div>
  <button id="hiddenButton">Show Me</button>

// SHOW BUTTON
  function showButtonAtTime() {
    if (currentTime >= startTime) { document.getElementById("hiddenButton").style.display = "block"; }
  }
  showButtonAtTime();

// HIDE BUTTON
  function hideButtonAtTime() { 
    if (currentTime >= endTime) { document.getElementById("hiddenButton").style.display = "none"; }
  }
  hideButtonAtTime();

// START RELOAD
  function refreshPage() { location.reload(); }
  var timeRemaining = startTime - new Date();
  if (timeRemaining > 0) { setTimeout(refreshPage, timeRemaining); }

// END RELOAD
  function refreshPage() { location.reload(); }
  var timeRemaining = endTime - new Date();
  if (timeRemaining > 0) { setTimeout(refreshPage, timeRemaining); }

// COUNTER
  const countdownInterval = setInterval(function () {
      const currentDate = new Date().getTime();
      const timeRemaining = startTime - currentDate;

if (timeRemaining <= 0) {
          clearInterval(countdownInterval);
          document.getElementById('countdown').display = none;
      } else {
          const days = Math.floor(timeRemaining / (1000 * 60 * 60 * 24));
          const hours = Math.floor((timeRemaining % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
          const minutes = Math.floor((timeRemaining % (1000 * 60 * 60)) / (1000 * 60));
          const seconds = Math.floor((timeRemaining % (1000 * 60)) / 1000);

document.getElementById('countdown').innerHTML = `${days}d ${hours}h ${minutes}m ${seconds}s`;
      }
  }, 1000);

</script>

</body>
</html>                                            
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