Youtubeのアーカイブから開始時間を調べるスクリプト

starttimestamp.js

(async () => {
	const f = await fetch(location.href);
	const html = await f.text();
	const index = html.indexOf('"startTimestamp');
	if (index < 0) {
		console.log('not found startTimestamp');
		return;
	}
	
	const count = html.indexOf(',', index) - index;
	return JSON.parse(`{${html.substr(index, count)}}`.replace(/\\/g,'')).startTimestamp;
})();