Use timezone-aware ISO 8601 for website timestamp

doc/conf.py

@@ -64,7 +64,26 @@
 # (Sphinx looks at variable changes and rewrites all files if some change)
 copyright = (  # noqa: A001
     f'2012–{td.year}, MNE Developers. Last updated <time datetime="{td.isoformat()}" class="localized">{td.strftime("%Y-%m-%d %H:%M %Z")}</time>\n'  # noqa: E501
-    '<script type="text/javascript">function formatTimestamp() {document.querySelectorAll("time.localized").forEach(el => el.textContent = new Date(el.getAttribute("datetime")).toLocaleString([], {dateStyle: "medium", timeStyle: "long"}));};if (document.readyState != "loading") formatTimestamp();else document.addEventListener("DOMContentLoaded", formatTimestamp);</script>'  # noqa: E501
+    """<script type="text/javascript">
+$(function () {
+    $("time.localized").each(function () {
+        var el = $(this);
+        var d = new Date(el.attr("datetime"));
+        var date = d.toLocaleDateString("sv-SE", {
+            year: "numeric",
+            month: "2-digit",
+            day: "2-digit"
+        });
+        var time = d.toLocaleTimeString([], {
+            hour: "2-digit",
+            minute: "2-digit",
+            hourCycle: "h23",
+            timeZoneName: "shortOffset"
+        });
+        el.text(`${date} ${time}`);
+    });
+});
+</script>"""
 )
 if os.getenv("MNE_FULL_DATE", "false").lower() != "true":
     copyright = f"2012–{td.year}, MNE Developers. Last updated locally."  # noqa: A001