diff --git a/main.py b/main.py
index a36d5f8..32e1ad8 100644
--- a/main.py
+++ b/main.py
@@ -30,6 +30,7 @@ from flask import (
     session,
     url_for,
 )
+from markupsafe import Markup
 from pygments import highlight
 from pygments.formatters import HtmlFormatter
 from pygments.lexers import TextLexer, guess_lexer
@@ -309,9 +310,12 @@ def load_logged_in_user() -> None:
 
 @app.template_filter("humandate")
 def humandate_filter(value: str) -> str:
+    """Return a <time> element that JS will convert to the viewer's local timezone."""
     try:
         dt = datetime.fromisoformat(value)
-        return dt.strftime("%b %-d, %Y at %-I:%M %p").lower()
+        iso = dt.isoformat()
+        fallback = dt.strftime("%b %-d, %Y at %-I:%M %p").lower()
+        return Markup(f'<time datetime="{iso}" class="js-localtime">{fallback}</time>')
     except Exception:
         return value
 
diff --git a/templates/base.html b/templates/base.html
index 1fc8a77..1136aaf 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -116,6 +116,17 @@
     {% endif %}
 
     <script>
+    // Convert UTC timestamps to local timezone
+    document.querySelectorAll('.js-localtime').forEach(function(el) {
+        var dt = new Date(el.getAttribute('datetime'));
+        if (!isNaN(dt)) {
+            var h = dt.getHours();
+            var ampm = h >= 12 ? 'pm' : 'am';
+            h = h % 12 || 12;
+            var months = ['jan','feb','mar','apr','may','jun','jul','aug','sep','oct','nov','dec'];
+            el.textContent = months[dt.getMonth()] + ' ' + dt.getDate() + ', ' + dt.getFullYear() + ' at ' + h + ':' + String(dt.getMinutes()).padStart(2,'0') + ' ' + ampm;
+        }
+    });
     // Profile links inside card links
     document.addEventListener('click', function(e) {
         var link = e.target.closest('.js-profile-link');