[Malleys]

Событие timeupdate

<video id="video1" controls autoplay loop src="https://sample-videos.com/video123/mp4/240/big_buck_bunny_240p_1mb.mp4"></video>
<output id="out"></output>
<script>
video1.addEventListener("timeupdate", (last => ({ target }) => {
	var p = target.currentTime >= 2; // или другое время вместо 2-ой секунды

	if(p && p !== last) {
		out.append(document.createElement("br"), "Event!", target.currentTime);
	}

	last = p;
})());

</script>

Или playing, если нужно вначале

<video id="video1" controls autoplay loop src="https://sample-videos.com/video123/mp4/240/big_buck_bunny_240p_1mb.mp4"></video>
<output id="out"></output>
<script>
video1.addEventListener("playing", ({ target }) => {
	if(target.currentTime < 1) out.append(document.createElement("br"), "Event!", target.currentTime);
});
</script>