diff --git a/docs/_javascript/preset_test.js b/docs/_javascript/preset_test.js
index da80c3e4..0e4eeecf 100644
--- a/docs/_javascript/preset_test.js
+++ b/docs/_javascript/preset_test.js
@@ -449,17 +449,27 @@
     }).format(new Date(milliseconds));
   }
 
+  function readableQueryValue(value) {
+    return encodeURIComponent(String(value))
+      .replace(/%3A/gi, ":")
+      .replace(/%2F/gi, "/");
+  }
+
   function configuredUrl(config, baseUrl) {
     const url = new URL(baseUrl);
-    url.search = "";
-    url.searchParams.set("start", new Date(config.startMs).toISOString());
-    url.searchParams.set("end", new Date(config.endMs).toISOString());
-    url.searchParams.set("tz", config.tz);
-    url.searchParams.set("freq", config.freqText);
-    url.searchParams.set("bw", config.bwText);
-    url.searchParams.set("sf", String(config.sf));
-    url.searchParams.set("cr", String(config.cr));
-    url.searchParams.set("tx", config.txText);
+    const values = [
+      ["start", new Date(config.startMs).toISOString()],
+      ["end", new Date(config.endMs).toISOString()],
+      ["tz", config.tz],
+      ["freq", config.freqText],
+      ["bw", config.bwText],
+      ["sf", String(config.sf)],
+      ["cr", String(config.cr)],
+      ["tx", config.txText],
+    ];
+    url.search = "?" + values.map(function (entry) {
+      return entry[0] + "=" + readableQueryValue(entry[1]);
+    }).join("&");
     return url.toString();
   }
 
diff --git a/docs/preset_test.md b/docs/preset_test.md
index a4e82241..5a18ecf6 100644
--- a/docs/preset_test.md
+++ b/docs/preset_test.md
@@ -266,9 +266,9 @@ clock</code></pre>
         <div class="preset-test-generator-disclosure-body">
           <p>
         Enter the test times in the selected time zone and choose the radio
-        tuple. The generated URL converts the times to exact UTC instants and
-        keeps <code>tz</code> so the page displays them in the organizer's local
-        time zone.
+        tuple. The generated URL converts the times to exact UTC instants, keeps
+        the date punctuation readable, and keeps <code>tz</code> so the page
+        displays them in the organizer's local time zone.
           </p>
 
       <div class="preset-test-generator-layout">
diff --git a/mkdocs.yml b/mkdocs.yml
index 15fd1127..a4c36316 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -28,4 +28,4 @@ extra_javascript:
   - _javascript/firmware_picker.js
   - _javascript/telemetry_decoder.js
   - _javascript/filter_tool.js
-  - _javascript/preset_test.js?v=20260916-4
+  - _javascript/preset_test.js?v=20260916-5
diff --git a/test/test_preset_test.js b/test/test_preset_test.js
index 28ce5e2a..d3aea8df 100644
--- a/test/test_preset_test.js
+++ b/test/test_preset_test.js
@@ -183,6 +183,12 @@ const shared = new URL(tool.configuredUrl(
   changed,
   "https://example.test/preset-test/?stale=yes#commands"
 ));
+assert.strictEqual(
+  shared.href,
+  "https://example.test/preset-test/?start=2026-09-22T00:00:00.000Z" +
+    "&end=2026-09-24T00:00:00.000Z&tz=America/Los_Angeles" +
+    "&freq=915.25&bw=125&sf=10&cr=5&tx=22#commands"
+);
 assert.strictEqual(shared.searchParams.get("start"), "2026-09-22T00:00:00.000Z");
 assert.strictEqual(shared.searchParams.get("end"), "2026-09-24T00:00:00.000Z");
 assert.strictEqual(shared.searchParams.get("freq"), "915.25");