function() {
var metaTags = document.getElementsByTagName('meta');
var pubDate = '';
for (var i = 0; i < metaTags.length; i++) {
if (metaTags[i].getAttribute('property') === 'article:published_time') {
pubDate = metaTags[i].getAttribute('content');
break;
}
}
if (pubDate) {
var date = new Date(pubDate);
var year = date.getFullYear();
var month = (date.getMonth() + 1).toString().padStart(2, '0');
var day = date.getDate().toString().padStart(2, '0');
return year + '-' + month + '-' + day;
}
return undefined;
}