diff --git a/src/components/OnThisDay.astro b/src/components/OnThisDay.astro
new file mode 100644
index 0000000..70581d9
--- /dev/null
+++ b/src/components/OnThisDay.astro
@@ -0,0 +1,133 @@
+<section class="on-this-day-band" aria-labelledby="on-this-day-title">
+  <div class="section-inner on-this-day-shell" data-on-this-day>
+    <div class="memory-date-card" aria-hidden="true">
+      <span data-memory-month>今日</span>
+      <strong data-memory-day>--</strong>
+      <small>北京时间</small>
+    </div>
+
+    <div class="on-this-day-content">
+      <div class="on-this-day-heading">
+        <div>
+          <p class="eyebrow">ON THIS DAY · 那年今日</p>
+          <h2 id="on-this-day-title">今天，记忆翻到了这一页</h2>
+        </div>
+        <p data-memory-summary aria-live="polite">正在寻找同月同日的班级记忆……</p>
+      </div>
+
+      <div class="memory-grid" data-memory-grid aria-live="polite" aria-busy="true"></div>
+
+      <div class="memory-empty" data-memory-empty hidden>
+        <span class="memory-empty-mark" aria-hidden="true">✦</span>
+        <div>
+          <h3>这一天还没有被写进纪念册</h3>
+          <p>也许只是故事还没整理好。先从其他日期里随手翻一页吧。</p>
+          <nav class="memory-empty-links" aria-label="浏览其他班级记忆">
+            <a href="/timeline/">班级时间线</a>
+            <a href="/gallery/">照片墙</a>
+            <a href="/articles/">文章归档</a>
+          </nav>
+        </div>
+      </div>
+
+      <noscript>
+        <p class="memory-noscript">启用 JavaScript 后，这里会根据北京时间自动展示当天的班级记忆。</p>
+      </noscript>
+    </div>
+  </div>
+</section>
+
+<script>
+  import { onThisDayMemories } from "../data/on-this-day";
+
+  const root = document.querySelector<HTMLElement>("[data-on-this-day]");
+
+  if (root) {
+    const dateParts = new Intl.DateTimeFormat("zh-CN", {
+      timeZone: "Asia/Shanghai",
+      year: "numeric",
+      month: "numeric",
+      day: "numeric"
+    }).formatToParts(new Date());
+    const dateValues = Object.fromEntries(dateParts.map((part) => [part.type, part.value]));
+    const month = Number(dateValues.month);
+    const day = Number(dateValues.day);
+    const currentYear = Number(dateValues.year);
+    const monthDay = `${String(month).padStart(2, "0")}-${String(day).padStart(2, "0")}`;
+    const matches = onThisDayMemories.filter((memory) => memory.monthDay === monthDay);
+    const visibleMatches = matches.slice(0, 6);
+
+    const monthLabel = root.querySelector<HTMLElement>("[data-memory-month]");
+    const dayLabel = root.querySelector<HTMLElement>("[data-memory-day]");
+    const summary = root.querySelector<HTMLElement>("[data-memory-summary]");
+    const grid = root.querySelector<HTMLElement>("[data-memory-grid]");
+    const empty = root.querySelector<HTMLElement>("[data-memory-empty]");
+
+    if (monthLabel) monthLabel.textContent = `${month}月`;
+    if (dayLabel) dayLabel.textContent = String(day).padStart(2, "0");
+
+    if (summary) {
+      summary.textContent = matches.length
+        ? `${month}月${day}日，找到了 ${matches.length} 条跨越不同年份的班级记忆。`
+        : `${month}月${day}日，今天暂时没有同月同日的记录。`;
+    }
+
+    if (grid) {
+      const fragment = document.createDocumentFragment();
+
+      visibleMatches.forEach((memory) => {
+        const card = document.createElement("a");
+        card.className = `memory-card memory-card-${memory.kind}`;
+        card.href = memory.href;
+        card.setAttribute("aria-label", `${memory.year}年${memory.kindLabel}：${memory.title}`);
+        if (memory.external) {
+          card.target = "_blank";
+          card.rel = "noreferrer";
+        }
+
+        if (memory.image) {
+          const image = document.createElement("img");
+          image.src = memory.image;
+          image.alt = "";
+          image.loading = "lazy";
+          card.append(image);
+        } else {
+          const visual = document.createElement("span");
+          visual.className = "memory-card-visual";
+          visual.setAttribute("aria-hidden", "true");
+          visual.textContent = "记";
+          card.append(visual);
+        }
+
+        const copy = document.createElement("span");
+        copy.className = "memory-card-copy";
+
+        const meta = document.createElement("span");
+        meta.className = "memory-card-meta";
+        const yearsAgo = currentYear - memory.year;
+        meta.textContent = `${memory.year}年 · ${yearsAgo > 0 ? `${yearsAgo}年前 · ` : ""}${memory.kindLabel}`;
+
+        const title = document.createElement("strong");
+        title.textContent = memory.title;
+
+        const text = document.createElement("span");
+        text.className = "memory-card-text";
+        text.textContent = memory.text;
+
+        const action = document.createElement("span");
+        action.className = "memory-card-action";
+        action.textContent = memory.external ? "阅读旧文章 ↗" : "翻开这段记忆 →";
+
+        copy.append(meta, title, text, action);
+        card.append(copy);
+        fragment.append(card);
+      });
+
+      grid.replaceChildren(fragment);
+      grid.hidden = matches.length === 0;
+      grid.setAttribute("aria-busy", "false");
+    }
+
+    if (empty) empty.hidden = matches.length > 0;
+  }
+</script>
diff --git a/src/data/on-this-day.ts b/src/data/on-this-day.ts
new file mode 100644
index 0000000..44777d2
--- /dev/null
+++ b/src/data/on-this-day.ts
@@ -0,0 +1,103 @@
+import { articles } from "./articles";
+import { photoTopics } from "./photos";
+import { timeline } from "./timeline";
+
+export type MemoryKind = "event" | "photo" | "article";
+
+export interface OnThisDayMemory {
+  id: string;
+  date: string;
+  monthDay: string;
+  year: number;
+  kind: MemoryKind;
+  kindLabel: string;
+  title: string;
+  text: string;
+  href: string;
+  image?: string;
+  external?: boolean;
+}
+
+const kindLabels: Record<MemoryKind, string> = {
+  event: "班级事件",
+  photo: "旧照片",
+  article: "旧文章"
+};
+
+const toIsoDate = (year: number, month: number, day: number) =>
+  `${year}-${String(month).padStart(2, "0")}-${String(day).padStart(2, "0")}`;
+
+const getTimelineDates = (label: string) => {
+  const match = label.match(/(\d{4})年(\d{1,2})月([^日]+)日/);
+  if (!match) return [];
+
+  const [, yearText, monthText, dayText] = match;
+  return dayText
+    .split(/[、,，]/)
+    .map((value) => Number(value.match(/\d+/)?.[0]))
+    .filter((value) => Number.isInteger(value) && value >= 1 && value <= 31)
+    .map((day) => toIsoDate(Number(yearText), Number(monthText), day));
+};
+
+const createMemory = (
+  memory: Omit<OnThisDayMemory, "monthDay" | "year" | "kindLabel">
+): OnThisDayMemory => ({
+  ...memory,
+  monthDay: memory.date.slice(5),
+  year: Number(memory.date.slice(0, 4)),
+  kindLabel: kindLabels[memory.kind]
+});
+
+const eventMemories = timeline.flatMap((moment, momentIndex) =>
+  getTimelineDates(moment.date).map((date) =>
+    createMemory({
+      id: `event-${momentIndex}-${date}`,
+      date,
+      kind: "event",
+      title: moment.title,
+      text: moment.text,
+      href: "href" in moment && typeof moment.href === "string" ? moment.href : "/timeline/"
+    })
+  )
+);
+
+const photoMemories = photoTopics.flatMap((topic) =>
+  topic.photos.flatMap((photo, photoIndex) =>
+    photo.date
+      ? [
+          createMemory({
+            id: `photo-${topic.slug}-${photoIndex}-${photo.date}`,
+            date: photo.date,
+            kind: "photo",
+            title: photo.title,
+            text: photo.caption,
+            href: `/gallery/${topic.slug}/`,
+            image: photo.image
+          })
+        ]
+      : []
+  )
+);
+
+const articleMemories = articles.map((article, articleIndex) =>
+  createMemory({
+    id: `article-${articleIndex}-${article.date}`,
+    date: article.date,
+    kind: "article",
+    title: article.title,
+    text: article.excerpt,
+    href: article.sourceUrl,
+    image: article.cover,
+    external: true
+  })
+);
+
+const kindOrder: Record<MemoryKind, number> = {
+  event: 0,
+  photo: 1,
+  article: 2
+};
+
+export const onThisDayMemories = [...eventMemories, ...photoMemories, ...articleMemories].sort(
+  (left, right) => right.year - left.year || kindOrder[left.kind] - kindOrder[right.kind]
+);
diff --git a/src/data/photo-topics/events.ts b/src/data/photo-topics/events.ts
index 840cf1e..a7db67d 100644
--- a/src/data/photo-topics/events.ts
+++ b/src/data/photo-topics/events.ts
@@ -10,7 +10,8 @@ export const eventsTopic: PhotoTopic = {
     {
       title: "高一下学期表彰大会",
       caption: "排练时觉得麻烦，回头看全是可爱。",
-      image: "https://pic.biss.click/image/50e233d6-dd88-4a10-bb2d-a42ace27cdec.jpg"
+      image: "https://pic.biss.click/image/50e233d6-dd88-4a10-bb2d-a42ace27cdec.jpg",
+      date: "2022-07-08"
     },
     {
       title: "集体出游",
@@ -20,13 +21,17 @@ export const eventsTopic: PhotoTopic = {
     {
       title: "百日誓师大会",
       caption: "高三的第一次全体活动，大家都很随意地在听讲，虽然最后还是没能坚持到最后。",
-      image: "https://pic.biss.click/image/45bfbe79-bd7b-40f3-9670-1b34cc0957b2.png"
+      image: "https://pic.biss.click/image/45bfbe79-bd7b-40f3-9670-1b34cc0957b2.png",
+      date: "2024-02-28"
     },
     wechatPhoto(117, "考前舞台", "紧张的日子里，也需要一次大声唱出来。"),
     wechatPhoto(121, "看台上的我们", "一片红色校服，聚成高三最后的集体活动。"),
     wechatPhoto(129, "操场热身", "阳光很好，口号和动作都比平时更有力量。"),
     wechatPhoto(132, "坐在一起", "台上发生什么已经模糊，身边的人还记得。"),
-    wechatPhoto(176, "元旦歌咏", "整齐站上舞台，是青春里难得的郑重。"),
+    {
+      ...wechatPhoto(176, "元旦歌咏", "整齐站上舞台，是青春里难得的郑重。"),
+      date: "2021-12-31"
+    },
     wechatPhoto(178, "领奖时刻", "证书会褪色，但被认可的那一刻不会。"),
     wechatPhoto(180, "操场挑战", "跨过栏架，也跨过一个个觉得做不到的瞬间。"),
     wechatPhoto(181, "百日倒计时", "数字揭开的那一刻，高考忽然变得很近。"),
diff --git a/src/data/photo-topics/graduation-day.ts b/src/data/photo-topics/graduation-day.ts
index 1817493..c44f891 100644
--- a/src/data/photo-topics/graduation-day.ts
+++ b/src/data/photo-topics/graduation-day.ts
@@ -32,13 +32,19 @@ export const graduationDayTopic: PhotoTopic = {
       caption: "那一刻大家都在笑，但心里都知道要分别了。",
       image: "https://pic.biss.click/image/f8d180c1-4827-4bfd-9550-4bfad4b97640.jpg"
     },
-    wechatPhoto(145, "壮行合影", "红色班服、彩色气球，和出发前最完整的一次站在一起。"),
+    {
+      ...wechatPhoto(145, "壮行合影", "红色班服、彩色气球，和出发前最完整的一次站在一起。"),
+      date: "2024-06-06"
+    },
     wechatPhoto(146, "气球升起之前", "所有人挤进镜头，等一个一起松手的瞬间。"),
     wechatPhoto(150, "飞向夏天", "气球越过教学楼，属于高中的倒计时也到了最后。"),
     wechatPhoto(151, "人群里的告别", "欢呼、拥抱和一句句被现场声音盖住的话。"),
     wechatPhoto(152, "穿过祝福", "从熟悉的人群中走过，前面就是新的路。"),
     wechatPhoto(153, "鲜花与笑脸", "最后一程依然有人在身旁鼓掌。"),
-    wechatPhoto(81, "毕业典礼合影", "红色幕布前，老师和同学一起留下毕业的证据。"),
+    {
+      ...wechatPhoto(81, "毕业典礼合影", "红色幕布前，老师和同学一起留下毕业的证据。"),
+      date: "2024-06-09"
+    },
     wechatPhoto(84, "典礼现场", "从看台望向舞台，礼堂装下了整届人的夏天。"),
     wechatPhoto(85, "把花送给老师", "镜头拼在一起，也拼出那天的感谢。"),
     wechatPhoto(88, "走过红毯", "熟悉的老师站在两侧，目送这一届学生离开。"),
diff --git a/src/data/photo-types.ts b/src/data/photo-types.ts
index 27449b5..3df2047 100644
--- a/src/data/photo-types.ts
+++ b/src/data/photo-types.ts
@@ -2,6 +2,7 @@ export interface PhotoItem {
   title: string;
   caption: string;
   image: string;
+  date?: string;
 }
 
 export interface PhotoTopic {
diff --git a/src/data/timeline.ts b/src/data/timeline.ts
index f071066..041f165 100644
--- a/src/data/timeline.ts
+++ b/src/data/timeline.ts
@@ -3,7 +3,14 @@ export const timelineIntro = {
   text: "把三年里的班级大事按时间放在这里。军训、分班、网课、百日誓师、高考和毕业，都成为了后来回头看时很亮的节点。"
 };
 
-export const timeline = [
+export interface TimelineMoment {
+  date: string;
+  title: string;
+  text: string;
+  href?: string;
+}
+
+export const timeline: TimelineMoment[] = [
   {
     date: "2021年8月",
     title: "进入高中",
diff --git a/src/pages/index.astro b/src/pages/index.astro
index 44f26f9..ea81d9c 100644
--- a/src/pages/index.astro
+++ b/src/pages/index.astro
@@ -1,5 +1,6 @@
 ---
 import BaseLayout from "../layouts/BaseLayout.astro";
+import OnThisDay from "../components/OnThisDay.astro";
 import { galleryIntro, photoTopics } from "../data/photos";
 import { featuredMessage, messages, messagesIntro } from "../data/messages";
 import { people, peopleIntro } from "../data/people";
@@ -41,6 +42,8 @@ const previewPeople = people.slice(0, 6);
   </aside>
 
   <main>
+    <OnThisDay />
+
     <section id="timeline">
       <div class="section-inner">
         <div class="section-title">
diff --git a/src/styles/global.css b/src/styles/global.css
index 4d78cd4..97354a6 100644
--- a/src/styles/global.css
+++ b/src/styles/global.css
@@ -198,6 +198,225 @@ h1 {
   font-size: 14px;
 }
 
+.on-this-day-band {
+  position: relative;
+  overflow: hidden;
+  background:
+    radial-gradient(circle at 8% 14%, rgba(232, 168, 76, 0.2), transparent 24%),
+    linear-gradient(135deg, #f6f0df, #fffdf7 48%, #eef4e9);
+}
+
+.on-this-day-band::after {
+  content: "";
+  position: absolute;
+  right: -80px;
+  bottom: -110px;
+  width: 280px;
+  height: 280px;
+  border: 1px solid rgba(55, 109, 90, 0.12);
+  border-radius: 50%;
+  box-shadow:
+    0 0 0 34px rgba(55, 109, 90, 0.035),
+    0 0 0 68px rgba(55, 109, 90, 0.025);
+  pointer-events: none;
+}
+
+.on-this-day-shell {
+  position: relative;
+  z-index: 1;
+  display: grid;
+  grid-template-columns: 150px minmax(0, 1fr);
+  gap: clamp(28px, 5vw, 64px);
+  align-items: start;
+}
+
+.memory-date-card {
+  position: sticky;
+  top: 26px;
+  overflow: hidden;
+  border: 1px solid rgba(55, 109, 90, 0.2);
+  border-radius: 14px;
+  background: #fffdf7;
+  box-shadow: 0 18px 42px rgba(39, 55, 52, 0.11);
+  text-align: center;
+}
+
+.memory-date-card span,
+.memory-date-card small {
+  display: block;
+}
+
+.memory-date-card span {
+  padding: 8px 12px;
+  background: var(--green);
+  color: #fffdf7;
+  font-size: 14px;
+  font-weight: 800;
+}
+
+.memory-date-card strong {
+  display: block;
+  padding: 12px 12px 2px;
+  color: var(--ink);
+  font-family: Georgia, "Times New Roman", serif;
+  font-size: 62px;
+  line-height: 1;
+}
+
+.memory-date-card small {
+  padding: 8px 12px 13px;
+  color: var(--muted);
+  font-size: 11px;
+  letter-spacing: 0.08em;
+}
+
+.on-this-day-heading {
+  display: grid;
+  grid-template-columns: minmax(0, 1fr) minmax(240px, 0.8fr);
+  gap: clamp(20px, 4vw, 52px);
+  align-items: end;
+  margin-bottom: 30px;
+}
+
+.on-this-day-heading .eyebrow {
+  color: var(--coral);
+}
+
+.on-this-day-heading p:last-child {
+  margin: 0;
+  color: var(--muted);
+}
+
+.memory-grid {
+  display: grid;
+  grid-template-columns: repeat(2, minmax(0, 1fr));
+  gap: 14px;
+}
+
+.memory-card {
+  min-height: 190px;
+  display: grid;
+  grid-template-columns: 150px minmax(0, 1fr);
+  overflow: hidden;
+  border: 1px solid rgba(31, 43, 42, 0.12);
+  border-radius: 12px;
+  background: rgba(255, 255, 255, 0.82);
+  box-shadow: 0 8px 28px rgba(39, 55, 52, 0.06);
+  transition: transform 180ms ease, border-color 180ms ease, box-shadow 180ms ease;
+}
+
+.memory-card:hover {
+  transform: translateY(-3px);
+  border-color: rgba(55, 109, 90, 0.34);
+  box-shadow: 0 16px 38px rgba(39, 55, 52, 0.12);
+}
+
+.memory-card > img,
+.memory-card-visual {
+  width: 100%;
+  height: 100%;
+  min-height: 190px;
+  object-fit: cover;
+}
+
+.memory-card-visual {
+  display: grid;
+  place-items: center;
+  color: rgba(255, 253, 247, 0.9);
+  background: linear-gradient(135deg, rgba(55, 109, 90, 0.94), rgba(69, 111, 148, 0.88));
+  font-family: STKaiti, KaiTi, serif;
+  font-size: 48px;
+}
+
+.memory-card-copy {
+  min-width: 0;
+  display: flex;
+  flex-direction: column;
+  align-items: flex-start;
+  padding: 20px;
+}
+
+.memory-card-meta {
+  color: var(--coral);
+  font-size: 12px;
+  font-weight: 800;
+  letter-spacing: 0.04em;
+}
+
+.memory-card-copy > strong {
+  margin-top: 7px;
+  font-size: 19px;
+  line-height: 1.35;
+}
+
+.memory-card-text {
+  display: -webkit-box;
+  overflow: hidden;
+  margin-top: 8px;
+  color: var(--muted);
+  font-size: 13px;
+  -webkit-box-orient: vertical;
+  -webkit-line-clamp: 2;
+}
+
+.memory-card-action {
+  margin-top: auto;
+  padding-top: 14px;
+  color: var(--green);
+  font-size: 12px;
+  font-weight: 800;
+}
+
+.memory-empty {
+  min-height: 190px;
+  display: grid;
+  grid-template-columns: auto minmax(0, 1fr);
+  gap: 22px;
+  align-items: center;
+  padding: clamp(24px, 4vw, 38px);
+  border: 1px dashed rgba(55, 109, 90, 0.3);
+  border-radius: 14px;
+  background: rgba(255, 255, 255, 0.56);
+}
+
+.memory-empty[hidden],
+.memory-grid[hidden] {
+  display: none;
+}
+
+.memory-empty-mark {
+  color: var(--sun);
+  font-size: 48px;
+}
+
+.memory-empty h3 {
+  margin: 0;
+  font-size: 22px;
+}
+
+.memory-empty p,
+.memory-noscript {
+  margin: 6px 0 0;
+  color: var(--muted);
+}
+
+.memory-empty-links {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 9px;
+  margin-top: 18px;
+}
+
+.memory-empty-links a {
+  padding: 7px 12px;
+  border: 1px solid var(--line);
+  border-radius: 999px;
+  background: #fff;
+  color: var(--green);
+  font-size: 13px;
+  font-weight: 800;
+}
+
 main {
   overflow: hidden;
 }
@@ -2227,6 +2446,8 @@ h2 {
 
   .stats,
   .section-title,
+  .on-this-day-shell,
+  .on-this-day-heading,
   .message-wall,
   .twikoo-sticky-wall .tk-comments,
   .twikoo-sticky-wall .tk-comments-container,
@@ -2428,6 +2649,16 @@ h2 {
     padding-inline: 14px;
   }
 
+  .memory-card {
+    grid-template-columns: 1fr;
+  }
+
+  .memory-card > img,
+  .memory-card-visual {
+    height: 190px;
+    min-height: 0;
+  }
+
   .hero-actions {
     display: grid;
   }
@@ -2442,6 +2673,19 @@ h2 {
     min-height: auto;
   }
 
+  .memory-date-card {
+    position: static;
+    width: 104px;
+  }
+
+  .memory-date-card strong {
+    font-size: 48px;
+  }
+
+  .memory-grid {
+    grid-template-columns: 1fr;
+  }
+
   .photo-card,
   .photo-card:nth-child(2),
   .photo-card:nth-child(4) {