diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 7a78da8..545b1ac 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -26,7 +26,7 @@ jobs:
     # cache key.
     - uses: actions/cache@v4
       with:
-        key: worm-scraper-cache-2025-01-02
+        key: worm-scraper-cache-2025-01-04
         path: ./cache
 
     - run: node ./lib/worm-scraper.js --book=worm
diff --git a/lib/convert.js b/lib/convert.js
index b22fbd8..75efc14 100644
--- a/lib/convert.js
+++ b/lib/convert.js
@@ -59,6 +59,7 @@ function getChapterData(arcs, manifest, chapterTitleStyle) {
       chapter.originalTitle = manifestEntry.title;
       chapter.usedTitle = chooseChapterTitle(chapter, chapterTitleStyle);
       chapter.datePublished = manifestEntry.datePublished;
+      chapter.dateModified = manifestEntry.dateModified;
     }
   }
 
diff --git a/lib/download.js b/lib/download.js
index fea5291..a3b9adf 100644
--- a/lib/download.js
+++ b/lib/download.js
@@ -70,11 +70,13 @@ async function downloadAllChapters(manifest, bookData, cachePath, manifestPath)
       const { contents, dom } = await downloadChapter(chapterURL);
       const title = getChapterTitle(dom.window.document);
       const datePublished = getChapterDatePublished(dom.window.document);
+      const dateModified = getChapterDateModified(dom.window.document);
 
       dom.window.close();
 
       manifest[manifestIndex].title = title;
       manifest[manifestIndex].datePublished = datePublished;
+      manifest[manifestIndex].dateModified = dateModified;
       manifest[manifestIndex].filename = filename;
       await fs.writeFile(path.resolve(cachePath, filename), contents);
 
@@ -105,7 +107,11 @@ function getChapterTitle(rawChapterDoc) {
 }
 
 function getChapterDatePublished(rawChapterDoc) {
-  return rawChapterDoc.querySelector(".entry-date").dateTime;
+  return rawChapterDoc.querySelector(`meta[property="article:published_time"]`).content;
+}
+
+function getChapterDateModified(rawChapterDoc) {
+  return rawChapterDoc.querySelector(`meta[property="article:modified_time"]`).content;
 }
 
 async function downloadChapter(url) {
diff --git a/lib/scaffold.js b/lib/scaffold.js
index 60838f5..87ed173 100644
--- a/lib/scaffold.js
+++ b/lib/scaffold.js
@@ -1,9 +1,12 @@
 "use strict";
 const fs = require("fs").promises;
 const path = require("path");
+const { name: packageName, version: packageVersion } = require("../package.json");
 
+const BOOK_SERIES = "Parahumans";
 const BOOK_PUBLISHER = "Domenic Denicola";
 const BOOK_AUTHOR = "Wildbow";
+const BOOK_GENERATOR = `${packageName} v${packageVersion}`;
 
 const STYLES_FILENAME = "chapter.css";
 const COVER_DOCUMENT_FILENAME = "cover.xhtml";
@@ -17,15 +20,15 @@ module.exports = async (
   bookPath,
   contentPath,
   chaptersPath,
-  augmentedChapterDataPath,
+  chapterDataPath,
   bookInfo
 ) => {
   await Promise.all([
     fs.cp(scaffoldingPath, bookPath, { recursive: true, filter: noThumbs }),
     fs.cp(coverImagePath, path.resolve(bookPath, "OEBPS", COVER_IMAGE_FILENAME)),
-    getChapterInfo(contentPath, chaptersPath, augmentedChapterDataPath).then(info => {
+    getChapterInfo(contentPath, chaptersPath, chapterDataPath).then(info => {
       return Promise.all([
-        writeOPF(contentPath, bookInfo, info.manifestAndSpineFiles, info.datePublished),
+        writeOPF(contentPath, bookInfo, info.manifestAndSpineFiles, info.datePublished, info.dateModified),
         writeNav(contentPath, info.manifestAndSpineFiles, info.tocHTML),
         writeArcTitlePages(chaptersPath, info.arcTitlePages)
       ]);
@@ -39,7 +42,7 @@ function noThumbs(filePath) {
   return path.basename(filePath) !== "Thumbs.db";
 }
 
-function writeOPF(contentPath, bookInfo, manifestAndSpineFiles, datePublished) {
+function writeOPF(contentPath, bookInfo, manifestAndSpineFiles, datePublished, dateModified) {
   const manifestItems = manifestAndSpineFiles.map(f => {
     return `    <item id="${f.id}" href="${f.href}" media-type="application/xhtml+xml"/>`;
   }).join("\n");
@@ -48,8 +51,6 @@ function writeOPF(contentPath, bookInfo, manifestAndSpineFiles, datePublished) {
     return `    <itemref idref="${f.id}"/>`;
   }).join("\n");
 
-  const dateWithoutMilliseconds = `${(new Date()).toISOString().split(".")[0]}Z`;
-
   // Note: per the spec at https://www.w3.org/TR/epub-33/#sec-group-position it seems like the collection-type should be
   // "set", but Calibre only recognizes "series" as of now:
   // https://github.com/kovidgoyal/calibre/blob/37dd0f5c70ebf8952d7be6dd7c37afd2a4fce9f0/src/calibre/ebooks/metadata/opf3.py#L792
@@ -65,16 +66,20 @@ function writeOPF(contentPath, bookInfo, manifestAndSpineFiles, datePublished) {
     <dc:title id="title">${bookInfo.title}</dc:title>
     <meta refines="#title" property="title-type">main</meta>
 
-    <meta property="belongs-to-collection" id="collection">Parahumans</meta>
+    <meta property="belongs-to-collection" id="collection">${BOOK_SERIES}</meta>
     <meta refines="#collection" property="collection-type">series</meta>
     <meta refines="#collection" property="group-position">${bookInfo.groupPosition}</meta>
 
     <dc:creator id="creator">${BOOK_AUTHOR}</dc:creator>
     <meta refines="#creator" property="role" scheme="marc:relators">aut</meta>
+
     <dc:publisher>${BOOK_PUBLISHER}</dc:publisher>
 
-    <dc:date>${datePublished}</dc:date>
-    <meta property="dcterms:modified">${dateWithoutMilliseconds}</meta>
+    <dc:contributor id="generator">${BOOK_GENERATOR}</dc:contributor>
+    <meta refines="#generator" property="role" scheme="marc:relators">bkp</meta>
+
+    <dc:date>${reformatDateString(datePublished)}</dc:date>
+    <meta property="dcterms:modified">${reformatDateString(dateModified)}</meta>
 
     <dc:description>${bookInfo.description}</dc:description>
   </metadata>
@@ -133,7 +138,8 @@ async function getChapterInfo(contentPath, chaptersPath, augmentedChapterDataPat
   const manifestAndSpineFiles = [];
   let tocHTML = "    <ol>\n";
   let arcIdCounter = 0;
-  let lastChapter;
+  let lastChapter, dateModified;
+  let dateModifiedTimestamp = 0;
   for (const arc of chapterData) {
     if (!arc.invisible) {
       const arcFilename = `arc${arcIdCounter}.xhtml`;
@@ -164,6 +170,13 @@ async function getChapterInfo(contentPath, chaptersPath, augmentedChapterDataPat
       tocHTML += `          <li><a href="${chapterHref}">${chapter.usedTitle}</a></li>\n`;
 
       lastChapter = chapter;
+
+      // The modification date of the book is the latest modification date of any chapter.
+      const thisDateModifiedTimestamp = (new Date(Date.parse(chapter.dateModified))).getTime();
+      if (thisDateModifiedTimestamp > dateModifiedTimestamp) {
+        dateModifiedTimestamp = thisDateModifiedTimestamp;
+        dateModified = chapter.dateModified;
+      }
     }
 
     if (!arc.invisible) {
@@ -179,7 +192,7 @@ async function getChapterInfo(contentPath, chaptersPath, augmentedChapterDataPat
   // We say that the publication date of the book is equal to the publication date of the last chapter.
   const { datePublished } = lastChapter;
 
-  return { arcTitlePages, manifestAndSpineFiles, tocHTML, datePublished };
+  return { arcTitlePages, manifestAndSpineFiles, tocHTML, datePublished, dateModified };
 }
 
 async function writeArcTitlePages(chaptersPath, arcTitlePages) {
@@ -207,3 +220,8 @@ async function writeArcTitlePages(chaptersPath, arcTitlePages) {
 function arcPlaintextTitle(arc) {
   return `${arc.label}: ${arc.title}`;
 }
+
+function reformatDateString(dateString) {
+  const date = new Date(dateString);
+  return date.toISOString().replace(".000", "");
+}