A solution using Promises, includes both progress bar & text countdown.
ProgressCountdown(10, 'pageBeginCountdown', 'pageBeginCountdownText').then(value => alert(`Page has started: ${value}.`));_x000D_
_x000D_
function ProgressCountdown(timeleft, bar, text) {_x000D_
return new Promise((resolve, reject) => {_x000D_
var countdownTimer = setInterval(() => {_x000D_
timeleft--;_x000D_
_x000D_
document.getElementById(bar).value = timeleft;_x000D_
document.getElementById(text).textContent = timeleft;_x000D_
_x000D_
if (timeleft <= 0) {_x000D_
clearInterval(countdownTimer);_x000D_
resolve(true);_x000D_
}_x000D_
}, 1000);_x000D_
});_x000D_
}
_x000D_
<div class="row begin-countdown">_x000D_
<div class="col-md-12 text-center">_x000D_
<progress value="10" max="10" id="pageBeginCountdown"></progress>_x000D_
<p> Begining in <span id="pageBeginCountdownText">10 </span> seconds</p>_x000D_
</div>_x000D_
</div>
_x000D_