feat: friendly relative dates ("10 minutes ago")

src/main/java/com/knowledgepixels/nanodash/Utils.java

@@ -10,6 +10,7 @@
 import org.apache.wicket.model.IModel;
 import org.apache.wicket.request.mapper.parameter.PageParameters;
 import org.apache.wicket.util.string.StringValue;
+import org.apache.wicket.util.string.Strings;
 import org.eclipse.rdf4j.model.IRI;
 import org.eclipse.rdf4j.model.Literal;
 import org.eclipse.rdf4j.model.Statement;
@@ -410,6 +411,39 @@ public static boolean looksLikeHtml(String value) {
         return LEADING_TAG.matcher(value).find();
     }
 
+    /**
+     * Matches an xsd:dateTime-style literal with a time component, e.g.
+     * "2026-04-16T08:27:12.954Z" or "2026-04-16T08:27:12+02:00".
+     */
+    private static final Pattern DATETIME_LITERAL =
+            Pattern.compile("^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(\\.\\d+)?(Z|[+-]\\d{2}:\\d{2})?$");
+
+    /**
+     * Checks whether a (raw query-result) string looks like an ISO-8601 date-time literal.
+     *
+     * @param value the string to check
+     * @return true if the string parses as an xsd:dateTime-style value
+     */
+    public static boolean isDateTimeLiteral(String value) {
+        return value != null && DATETIME_LITERAL.matcher(value).matches();
+    }
+
+    /**
+     * Renders a {@code <time>} element for an ISO-8601 date-time value. The machine-readable
+     * value goes in the {@code datetime} attribute; client-side script (nanodash.js) rewrites
+     * the visible text to a relative form ("10 minutes ago") in the viewer's local timezone and
+     * puts the absolute date-time in the tooltip. If script does not run, {@code fallbackText}
+     * remains visible.
+     *
+     * @param isoValue     the ISO-8601 date-time string (machine-readable)
+     * @param fallbackText the human-readable text shown when script is unavailable
+     * @return an HTML {@code <time>} element string (caller must render with escaping disabled)
+     */
+    public static String friendlyDateHtml(String isoValue, String fallbackText) {
+        return "<time class=\"friendly-date\" datetime=\"" + Strings.escapeMarkup(isoValue) + "\">"
+                + Strings.escapeMarkup(fallbackText) + "</time>";
+    }
+
     /**
      * Converts PageParameters to a URL-encoded string representation.
      *

src/main/java/com/knowledgepixels/nanodash/component/NanopubItem.java

@@ -145,7 +145,10 @@ protected void populateItem(Item<IRI> item) {
         } else {
             WebMarkupContainer footer = new WebMarkupContainer("footer");
             if (n.getCreationTime() != null) {
-                footer.add(new Label("datetime", simpleDateTimeFormat.format(n.getCreationTime().getTime())));
+                // Friendly relative time client-side; server-formatted date is the no-script fallback.
+                String iso = n.getCreationTime().toInstant().toString();
+                String fallback = simpleDateTimeFormat.format(n.getCreationTime().getTime());
+                footer.add(new Label("datetime", Utils.friendlyDateHtml(iso, fallback)).setEscapeModelStrings(false));
             } else {
                 footer.add(new Label("datetime", "(undated)"));
             }

src/main/java/com/knowledgepixels/nanodash/component/QueryResultTable.java

@@ -263,6 +263,9 @@ public void populateItem(Item<ICellPopulator<ApiResponseEntry>> cellItem, String
                     } else {
                         if (key.startsWith("pubkey")) {
                             cellItem.add(new Label(componentId, value).add(new AttributeAppender("style", "overflow-wrap: anywhere;")));
+                        } else if (Utils.isDateTimeLiteral(value)) {
+                            // Show a friendly relative time (client-side); raw ISO value stays as no-script fallback.
+                            cellItem.add(new Label(componentId, Utils.friendlyDateHtml(value, value)).setEscapeModelStrings(false));
                         } else {
                             Label cellLabel;
                             if (Utils.looksLikeHtml(value)) {

src/main/java/com/knowledgepixels/nanodash/script/nanodash.js

@@ -15,11 +15,49 @@ function wrapLeadingEmoji() {
     node.parentNode.insertBefore(span, node);
   });
 }
+/* Friendly date rendering — turns <time class="friendly-date" datetime="..."> into a
+   relative form ("10 minutes ago") in the viewer's local timezone, with the absolute
+   date-time in the tooltip. Falls back silently to the server-rendered text if the value
+   does not parse. No jQuery dependency; safe to call repeatedly (idempotent). */
+function friendlyRelative(date, absDateFallback) {
+  var diffSec = Math.round((date.getTime() - Date.now()) / 1000); // negative = past
+  if (Math.abs(diffSec) < 45) return "just now";
+  if (typeof Intl === "undefined" || !Intl.RelativeTimeFormat) return absDateFallback;
+  var rtf = new Intl.RelativeTimeFormat(undefined, { numeric: "auto" });
+  var min = Math.round(diffSec / 60);
+  if (Math.abs(min) < 60) return rtf.format(min, "minute");
+  var hr = Math.round(diffSec / 3600);
+  if (Math.abs(hr) < 24) return rtf.format(hr, "hour");
+  var day = Math.round(diffSec / 86400);
+  if (Math.abs(day) < 7) return rtf.format(day, "day");
+  return absDateFallback; // older than a week → absolute date
+}
+
+function renderFriendlyDates(root) {
+  var scope = root || document;
+  scope.querySelectorAll("time.friendly-date[datetime]").forEach(function (el) {
+    if (el.dataset.friendlyRendered === "1") return;
+    var d = new Date(el.getAttribute("datetime"));
+    if (isNaN(d.getTime())) return; // unparseable → leave server-rendered text as-is
+    el.dataset.friendlyRendered = "1";
+    // Full, pretty tooltip: weekday + full date + time with seconds and timezone,
+    // e.g. "Thursday, 16 April 2026 at 10:27:12 CEST".
+    var absFull = d.toLocaleString(undefined, { dateStyle: "full", timeStyle: "long" });
+    var absDate = d.toLocaleDateString(undefined, { dateStyle: "medium" });
+    el.setAttribute("title", absFull);
+    el.textContent = friendlyRelative(d, absDate);
+  });
+}
+
 document.addEventListener("DOMContentLoaded", function() {
   wrapLeadingEmoji();
+  renderFriendlyDates();
   // Re-run after Wicket AJAX calls complete (dynamically loaded content)
   if (typeof Wicket !== "undefined" && Wicket.Event) {
-    Wicket.Event.subscribe("/ajax/call/complete", wrapLeadingEmoji);
+    Wicket.Event.subscribe("/ajax/call/complete", function() {
+      wrapLeadingEmoji();
+      renderFriendlyDates();
+    });
   }
 });
 
@@ -38,6 +76,7 @@ $(window).on('load', updateElements);
 
 function updateElements() {
   wrapLeadingEmoji();
+  renderFriendlyDates();
   adjustValueWidths();
   setCollapseOverflow();
   collapseNanopubAssertions();