diff --git a/frontend/static/cache.js b/frontend/static/cache.js
index 33fe40c..ee04bf5 100644
--- a/frontend/static/cache.js
+++ b/frontend/static/cache.js
@@ -207,7 +207,7 @@ function seedCache(url, data, etag) {
 // lives here next to the bundle fetch — not knowledge of any one page.
 function viewFetches(q, today) {
   return {
-    grade:    [uv(`grade?${q}`), TTL.grade],
+    grade:    [uv(`grade?${q}&date=${today}`), TTL.grade],
     forecast: [uv(`forecast?${q}`), TTL.forecast],
     calendar: [uv(`calendar?${q}&months=24`), TTL.calendar],
     day:      [uv(`day?${q}&date=${today}`), TTL.day],
@@ -232,6 +232,12 @@ export function prefetchViews(lat, lon, ownViews) {
   if (_prefetched === tag) return;
   _prefetched = tag;
   const q = `lat=${lat}&lon=${lon}`;
+  // The client's local "today" — sent explicitly so the server never has to guess
+  // it from its own (UTC) clock. Getting this wrong is exactly what poisoned the
+  // Weekly view's cache for UTC+ visitors between their local midnight and UTC
+  // midnight: the bundle used to be built against the server's date while the
+  // per-view request stated the client's, so the two silently disagreed.
+  const today = localDay();
   const own = new Set(ownViews);
   // Yield first so the landing view finishes rendering before we fetch the rest.
   setTimeout(async () => {
@@ -239,17 +245,20 @@ export function prefetchViews(lat, lon, ownViews) {
       const ek = "tg-cell-etag:" + q;
       let prev = null;
       try { prev = sessionStorage.getItem(ek); } catch (e) {}
-      const res = await fetch(uv(`cell?${q}&neighbors=1`),
+      const res = await fetch(uv(`cell?${q}&date=${today}&neighbors=1`),
         { credentials: "include", ...(prev ? { headers: { "If-None-Match": prev } } : {}) });
       if (res.ok && res.status !== 304) {
         const bundle = await res.json();
         try { sessionStorage.setItem(ek, res.headers.get("ETag") || ""); } catch (e) {}
-        const fetches = viewFetches(q, localDay());
+        // Seed under bundle.today (the date the server actually resolved — normally
+        // just an echo of the date= we sent) rather than our own `today`, so the
+        // seeded key stays byte-identical to what a per-view request for that same
+        // resolved date will use even in the rare case the two disagree (e.g. a
+        // request that straddles local midnight).
+        const fetches = viewFetches(q, bundle.today);
         for (const [name, slice] of Object.entries(bundle.slices || {})) {
           if (own.has(name) || !slice || !slice.data) continue;
-          const url = name === "day"
-            ? uv(`day?${q}&date=${bundle.today}`)   // the day slice targets today
-            : (fetches[name] || [])[0];
+          const url = (fetches[name] || [])[0];
           if (url) seedCache(url, slice.data, slice.etag);
         }
       }