www/html/wordle/game.html

@@ -316,8 +316,11 @@ async function loadBoard() {
 
     // If we know the exact epoch day and haven't set date text yet, show it
     if (finalEpoch !== null && !dateEl.textContent) {
+        // Epoch days start at midnight UTC, so format in UTC or viewers
+        // west of UTC see the previous day
         dateEl.textContent = new Date(finalEpoch * 86400 * 1000)
             .toLocaleDateString(undefined, {
+                timeZone: "UTC",
                 weekday: "long",
                 year: "numeric",
                 month: "long",

www/html/wordle/games.html

@@ -134,8 +134,11 @@
 
 <script>
 function formatDateFromEpochDays(epochDays) {
+  // Epoch days start at midnight UTC, so format in UTC or viewers
+  // west of UTC see the previous day
   const date = new Date(epochDays * 86400 * 1000);
   return date.toLocaleDateString(undefined, {
+    timeZone: "UTC",
     weekday: "short",
     year: "numeric",
     month: "short",