🐛 Look for lastBuildDate if pubDate doesn't exist

index.js

@@ -60,7 +60,7 @@ export const fetchFeed = async (url, lastPublishedDates) => {
     return items.map(item => ({
       title: item.title,
       link: item.link,
-      publishedDate: new Date(item.pubDate).toISOString(),
+      publishedDate: new Date(item.pubDate || item.lastBuildDate).toISOString(),
     })).filter(article => {
       let lastPublished = lastPublishedDates[url];
       let isNew = !lastPublished || new Date(article.publishedDate) > new Date(lastPublished);