diff --git a/index.html b/index.html
index 7d9e085..66a9309 100644
--- a/index.html
+++ b/index.html
@@ -842,6 +842,22 @@ var effect = (VANTA.CLOUDS2 || VANTA.CLOUDS)({
         function updateClockAndEvents() {
             var now = new Date();
 
+            // Calculate real day progress based on sun position
+            // 0% = midnight, 50% = noon, 100% = next midnight
+            var sunTimes = SunCalc.getTimes(now, PASSAU_LAT, PASSAU_LON);
+            var sunrise = sunTimes.sunrise;
+            var sunset = sunTimes.sunset;
+            var realDayProgress;
+            if (now < sunrise) {
+                var prevSunset = new Date(sunset.getTime() - 24 * 3600 * 1000);
+                realDayProgress = (now.getTime() - prevSunset.getTime()) / (sunrise.getTime() - prevSunset.getTime());
+            } else if (now < sunset) {
+                realDayProgress = 0.5 + (now.getTime() - sunrise.getTime()) / (sunset.getTime() - sunrise.getTime()) * 0.5;
+            } else {
+                realDayProgress = 0.5 + (now.getTime() - sunset.getTime()) / (sunrise.getTime() + 24 * 3600 * 1000 - sunset.getTime()) * 0.5;
+            }
+            realDayProgress = Math.max(0, Math.min(1, realDayProgress));
+
             // Real-time clock hands and digital
             var h = now.getHours();
             var m = now.getMinutes();
@@ -1082,12 +1098,12 @@ var weatherThemes = {
             return (now.getTime() - startOfDay.getTime()) / 86400000;
         }
 
-        function updateDebug(t, palette, vantaColors, themeName) {
+        function updateDebug(t, palette, vantaColors, themeName, realDayProgress) {
             var now = new Date();
             var hh = now.getHours(), mm = now.getMinutes(), ss = now.getSeconds();
             document.getElementById('dbg-time').textContent =
                 (hh < 10 ? '0' : '') + hh + ':' + (mm < 10 ? '0' : '') + mm + ':' + (ss < 10 ? '0' : '') + ss;
-            document.getElementById('dbg-day').textContent = (t * 100).toFixed(1) + '%';
+            document.getElementById('dbg-day').textContent = realDayProgress != null ? (realDayProgress * 100).toFixed(1) + '%' : (t * 100).toFixed(1) + '%';
             document.getElementById('dbg-weather').textContent =
                 currentWeatherCode + ' (' + (weatherThemes[themeName] ? themeName : '?') + ')';
             document.getElementById('dbg-theme').textContent = themeName || '-';
@@ -1184,7 +1200,7 @@ var weatherThemes = {
                 speed: currentThemeSpeed
             });
             document.body.style.backgroundColor = '#' + ('00000' + c.sky.toString(16)).slice(-6);
-            updateDebug(t, null, c, currentWeatherThemeName);
+            updateDebug(t, null, c, currentWeatherThemeName, realDayProgress);
             requestAnimationFrame(animate);
         }