diff --git a/frontend/src/tools/devtools.jsx b/frontend/src/tools/devtools.jsx
index 3843bfd..2ec5b88 100644
--- a/frontend/src/tools/devtools.jsx
+++ b/frontend/src/tools/devtools.jsx
@@ -478,10 +478,31 @@ function ElektroRechner({ mobile }) {
 }
 
 // ─────────────────────────────────────────────────────────────── Datetime ──
-const MOSES_EPOCH = new Date('1970-01-01T00:00:00Z'); // Moseszeit = Unix time (Sekunden)
+// Moseszeit: Unix-Timestamp (Sekunden), aber Jahreszahl wird um +3 Jahre versetzt angezeigt.
+// Beispiel: 1685560872 → Unix=2023-05-31 19:21:12 UTC → Moses-Anzeige=2026-05-31 19:21:12
+// Umkehrung: Moses-Jahr -3 → Unix-Jahr → Timestamp berechnen.
+const MOSES_YEAR_OFFSET = 3;
 
 function pad2(n){ return String(n).padStart(2,'0'); }
 
+// Aus Unix-Timestamp (ms) ein Anzeige-Objekt für Moseszeit bauen (UTC + Jahr+3)
+function mosesDisplayFromUnixMs(ms) {
+  const d = new Date(ms);
+  const y = d.getUTCFullYear() + MOSES_YEAR_OFFSET;
+  const mo= pad2(d.getUTCMonth()+1);
+  const day=pad2(d.getUTCDate());
+  const h = pad2(d.getUTCHours());
+  const mi= pad2(d.getUTCMinutes());
+  const s = pad2(d.getUTCSeconds());
+  return { de: `${day}.${mo}.${y} ${h}:${mi}:${s}`, iso: `${y}-${mo}-${day}T${h}:${mi}:${s}` };
+}
+
+// Aus Moses-Sekunden → Unix-Timestamp in ms (einfach *1000, Jahr-Versatz ist nur Anzeige)
+function mosesToUnixMs(mosesTs) {
+  return mosesTs * 1000;
+}
+
+// Aus lokalem datetime-local Input (local time) ein Date-Objekt
 function toLocalISO(d){
   return `${d.getFullYear()}-${pad2(d.getMonth()+1)}-${pad2(d.getDate())}T${pad2(d.getHours())}:${pad2(d.getMinutes())}:${pad2(d.getSeconds())}`;
 }
@@ -510,25 +531,38 @@ function DatetimeRechner({ mobile }) {
   function convFromUnix(val) {
     const n = parseInt(val);
     if (isNaN(n)) { setConvResult(null); return; }
-    const d = new Date(n * 1000);
+    const unixMs = mosesToUnixMs(n);
+    const d = new Date(unixMs);
+    const moses = mosesDisplayFromUnixMs(unixMs);
+    const dLocal = new Date(n * 1000); // for weekday (UTC)
     setConvResult({
-      de:    formatDE(d),
-      local: toLocalISO(d),
+      de:    moses.de,
+      local: moses.iso,
       unix:  String(n),
-      wday:  WEEKDAYS[d.getDay()],
+      wday:  WEEKDAYS[d.getUTCDay()],
       kw:    getKW(d),
     });
   }
 
   function convFromLocal(val) {
+    // val is in format YYYY-MM-DDTHH:MM:SS from datetime-local (local browser time)
+    // For Moses: treat it as UTC (since Moses timestamps are UTC-based + year offset)
     if (!val) { setConvResult(null); return; }
-    const d = new Date(val);
+    // Parse the value: year shown is Moses year, so subtract 3 for real UTC year
+    const [datePart, timePart] = val.split('T');
+    if (!datePart || !timePart) { setConvResult(null); return; }
+    const [y, mo, day] = datePart.split('-').map(Number);
+    const [h, mi, s]   = timePart.split(':').map(Number);
+    const realYear = y - MOSES_YEAR_OFFSET;
+    const d = new Date(Date.UTC(realYear, mo-1, day, h, mi, s||0));
     if (isNaN(d)) { setConvResult(null); return; }
+    const unixSec = Math.floor(d.getTime() / 1000);
+    const moses = mosesDisplayFromUnixMs(d.getTime());
     setConvResult({
-      de:    formatDE(d),
-      local: toLocalISO(d),
-      unix:  String(Math.floor(d.getTime()/1000)),
-      wday:  WEEKDAYS[d.getDay()],
+      de:    moses.de,
+      local: val,
+      unix:  String(unixSec),
+      wday:  WEEKDAYS[d.getUTCDay()],
       kw:    getKW(d),
     });
   }
@@ -620,7 +654,13 @@ function DatetimeRechner({ mobile }) {
             </div>
           </div>
           <button style={{...S.btn('#4ecdc4',false), fontSize:11, padding:'6px 14px', marginBottom:16}}
-            onClick={()=>{ const d=new Date(); const v=String(Math.floor(d.getTime()/1000)); setConv({unix:v,local:toLocalISO(d),de:''}); convFromUnix(v); }}>
+            onClick={()=>{
+              const d = new Date();
+              const unixSec = Math.floor(d.getTime()/1000);
+              const moses = mosesDisplayFromUnixMs(d.getTime());
+              setConv({unix:String(unixSec), local:moses.iso, de:''});
+              convFromUnix(String(unixSec));
+            }}>
             Jetzt verwenden
           </button>
           {convResult && (
@@ -642,6 +682,7 @@ function DatetimeRechner({ mobile }) {
             <div style={{color:'rgba(255,255,255,0.45)',fontFamily:'monospace',fontSize:9,marginBottom:6}}>BEISPIEL</div>
             <div style={{color:'rgba(255,255,255,0.6)',fontFamily:'monospace',fontSize:11}}>
               Moseszeit <code style={{color:'#4ecdc4'}}>1685554093</code> = <code style={{color:'#4ecdc4'}}>31.05.2026 17:28:13</code>
+              <span style={{color:'rgba(255,255,255,0.4)',fontSize:10,marginLeft:8}}>(UTC, Jahr+3 Versatz)</span>
             </div>
           </div>
         </div>