diff --git a/ksql-engine/src/test/resources/query-validation-tests/hopping-windows.json b/ksql-engine/src/test/resources/query-validation-tests/hopping-windows.json
index 94a2bc1779d0..363eb9089bfd 100644
--- a/ksql-engine/src/test/resources/query-validation-tests/hopping-windows.json
+++ b/ksql-engine/src/test/resources/query-validation-tests/hopping-windows.json
@@ -25,22 +25,22 @@
       ],
       "outputs": [
         {"topic": "S2", "key": 0, "value": "0,0", "timestamp": 0, "window": {"start": 0, "end": 30000}},
-        {"topic": "S2", "key": 0, "value": "0,5", "timestamp": 0, "window": {"start": 0, "end": 30000}},
+        {"topic": "S2", "key": 0, "value": "0,5", "timestamp": 10000, "window": {"start": 0, "end": 30000}},
         {"topic": "S2", "key": 0, "value": "0,5", "timestamp": 10000, "window": {"start": 10000, "end": 40000}},
-        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 10000, "window": {"start": 10000, "end": 40000}},
-        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 20000, "window": {"start": 20000, "end": 50000}},
+        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 30000, "window": {"start": 10000, "end": 40000}},
+        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 30000, "window": {"start": 20000, "end": 50000}},
         {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 30000, "window": {"start": 30000, "end": 60000}},
-        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 20000, "window": {"start": 20000, "end": 50000}},
-        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 30000, "window": {"start": 30000, "end": 60000}},
-        {"topic": "S2", "key": 100, "value": "100,6", "timestamp": 40000, "window": {"start": 40000, "end": 70000}},
-        {"topic": "S2", "key": 100, "value": "100,300", "timestamp": 30000, "window": {"start": 30000, "end": 60000}},
-        {"topic": "S2", "key": 100, "value": "100,300", "timestamp": 40000, "window": {"start": 40000, "end": 70000}},
+        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 45000, "window": {"start": 20000, "end": 50000}},
+        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 45000, "window": {"start": 30000, "end": 60000}},
+        {"topic": "S2", "key": 100, "value": "100,6", "timestamp": 45000, "window": {"start": 40000, "end": 70000}},
+        {"topic": "S2", "key": 100, "value": "100,300", "timestamp": 50000, "window": {"start": 30000, "end": 60000}},
+        {"topic": "S2", "key": 100, "value": "100,300", "timestamp": 50000, "window": {"start": 40000, "end": 70000}},
         {"topic": "S2", "key": 100, "value": "100,300", "timestamp": 50000, "window": {"start": 50000, "end": 80000}},
-        {"topic": "S2", "key": 0, "value": "0,100", "timestamp": 10000, "window": {"start": 10000, "end": 40000}},
-        {"topic": "S2", "key": 0, "value": "0,100", "timestamp": 20000, "window": {"start": 20000, "end": 50000}},
-        {"topic": "S2", "key": 0, "value": "0,100", "timestamp": 30000, "window": {"start": 30000, "end": 60000}},
-        {"topic": "S2", "key": 0, "value": "0,2000", "timestamp": 20000, "window": {"start": 20000, "end": 50000}},
-        {"topic": "S2", "key": 0, "value": "0,2000", "timestamp": 30000, "window": {"start": 30000, "end": 60000}},
+        {"topic": "S2", "key": 0, "value": "0,100", "timestamp": 35000, "window": {"start": 10000, "end": 40000}},
+        {"topic": "S2", "key": 0, "value": "0,100", "timestamp": 35000, "window": {"start": 20000, "end": 50000}},
+        {"topic": "S2", "key": 0, "value": "0,100", "timestamp": 35000, "window": {"start": 30000, "end": 60000}},
+        {"topic": "S2", "key": 0, "value": "0,2000", "timestamp": 40000, "window": {"start": 20000, "end": 50000}},
+        {"topic": "S2", "key": 0, "value": "0,2000", "timestamp": 40000, "window": {"start": 30000, "end": 60000}},
         {"topic": "S2", "key": 0, "value": "0,2000", "timestamp": 40000, "window": {"start": 40000, "end": 70000}}
 
       ]
@@ -58,10 +58,10 @@
       ],
       "outputs": [
         {"topic": "S2", "key": 0, "value": "0,0", "timestamp": 0, "window": {"start": 0, "end": 30000}},
-        {"topic": "S2", "key": 0, "value": "0,0", "timestamp": 0, "window": {"start": 0, "end": 30000}},
+        {"topic": "S2", "key": 0, "value": "0,0", "timestamp": 10000, "window": {"start": 0, "end": 30000}},
         {"topic": "S2", "key": 0, "value": "0,5", "timestamp": 10000, "window": {"start": 10000, "end": 40000}},
-        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 10000, "window": {"start": 10000, "end": 40000}},
-        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 20000, "window": {"start": 20000, "end": 50000}},
+        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 30000, "window": {"start": 10000, "end": 40000}},
+        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 30000, "window": {"start": 20000, "end": 50000}},
         {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 30000, "window": {"start": 30000, "end": 60000}}
       ]
     },
@@ -77,7 +77,7 @@
       ],
       "outputs": [
         {"topic": "S2", "key": 0, "value": {"ID":0,"TOPK":[0.0]}, "timestamp": 0, "window": {"start": 0, "end": 30000}},
-        {"topic": "S2", "key": 0, "value": {"ID":0,"TOPK":[100.0,0.0]}, "timestamp": 0, "window": {"start": 0, "end": 30000}},
+        {"topic": "S2", "key": 0, "value": {"ID":0,"TOPK":[100.0,0.0]}, "timestamp": 10000, "window": {"start": 0, "end": 30000}},
         {"topic": "S2", "key": 0, "value": {"ID":0,"TOPK":[100.0]}, "timestamp": 10000, "window": {"start": 10000, "end": 40000}}
       ]
     },
@@ -94,9 +94,9 @@
       ],
       "outputs": [
         {"topic": "S2", "key": 0, "value": {"ID":0,"TOPK":[0.0]}, "timestamp": 0, "window": {"start": 0, "end": 30000}},
-        {"topic": "S2", "key": 0, "value": {"ID":0,"TOPK":[100.0,0.0]}, "timestamp": 0, "window": {"start": 0, "end": 30000}},
+        {"topic": "S2", "key": 0, "value": {"ID":0,"TOPK":[100.0,0.0]}, "timestamp": 10000, "window": {"start": 0, "end": 30000}},
         {"topic": "S2", "key": 0, "value": {"ID":0,"TOPK":[100.0]}, "timestamp": 10000, "window": {"start": 10000, "end": 40000}},
-        {"topic": "S2", "key": 0, "value": {"ID":0,"TOPK":[100.0,0.0]}, "timestamp": 0, "window": {"start": 0, "end": 30000}},
+        {"topic": "S2", "key": 0, "value": {"ID":0,"TOPK":[100.0,0.0]}, "timestamp": 10000, "window": {"start": 0, "end": 30000}},
         {"topic": "S2", "key": 0, "value": {"ID":0,"TOPK":[100.0]}, "timestamp": 10000, "window": {"start": 10000, "end": 40000}}
       ]
     }
diff --git a/ksql-engine/src/test/resources/query-validation-tests/session-windows.json b/ksql-engine/src/test/resources/query-validation-tests/session-windows.json
index 6220b88e0318..fe969c40be6b 100644
--- a/ksql-engine/src/test/resources/query-validation-tests/session-windows.json
+++ b/ksql-engine/src/test/resources/query-validation-tests/session-windows.json
@@ -22,10 +22,10 @@
       ],
       "outputs": [
         {"topic": "S2", "key": 0, "value": "0,0", "timestamp": 0, "window": {"start": 0, "end": 30000}},
-        {"topic": "S2", "key": 0, "value": null, "timestamp": 0, "window": {"start": 0, "end": 30000}},
+        {"topic": "S2", "key": 0, "value": null, "timestamp": 10000, "window": {"start": 0, "end": 30000}},
         {"topic": "S2", "key": 0, "value": "0,5", "timestamp": 10000, "window": {"start": 0, "end": 40000}},
         {"topic": "S2", "key": 1, "value": "1,100", "timestamp": 10000, "window": {"start": 10000, "end": 40000}},
-        {"topic": "S2", "key": 1, "value": null, "timestamp": 10000, "window": {"start": 10000, "end": 40000}},
+        {"topic": "S2", "key": 1, "value": null, "timestamp": 40000, "window": {"start": 10000, "end": 40000}},
         {"topic": "S2", "key": 1, "value": "1,200", "timestamp": 40000, "window": {"start": 10000, "end": 70000}}
       ]
     }
diff --git a/ksql-engine/src/test/resources/query-validation-tests/tumbling-windows.json b/ksql-engine/src/test/resources/query-validation-tests/tumbling-windows.json
index 346c3f81cd22..f468ae5c612a 100644
--- a/ksql-engine/src/test/resources/query-validation-tests/tumbling-windows.json
+++ b/ksql-engine/src/test/resources/query-validation-tests/tumbling-windows.json
@@ -25,12 +25,12 @@
       ],
       "outputs": [
         {"topic": "S2", "key": 0, "value": "0,0", "timestamp": 0, "window": {"start": 0, "end": 30000}},
-        {"topic": "S2", "key": 0, "value": "0,5", "timestamp": 0, "window": {"start": 0, "end": 30000}},
+        {"topic": "S2", "key": 0, "value": "0,5", "timestamp": 10000, "window": {"start": 0, "end": 30000}},
         {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 30000, "window": {"start": 30000, "end": 60000}},
-        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 30000, "window": {"start": 30000, "end": 60000}},
-        {"topic": "S2", "key": 100, "value": "100,300", "timestamp": 30000, "window": {"start": 30000, "end": 60000}},
-        {"topic": "S2", "key": 0, "value": "0,100", "timestamp": 30000, "window": {"start": 30000, "end": 60000}},
-        {"topic": "S2", "key": 0, "value": "0,2000", "timestamp": 30000, "window": {"start": 30000, "end": 60000}}
+        {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 45000, "window": {"start": 30000, "end": 60000}},
+        {"topic": "S2", "key": 100, "value": "100,300", "timestamp": 50000, "window": {"start": 30000, "end": 60000}},
+        {"topic": "S2", "key": 0, "value": "0,100", "timestamp": 35000, "window": {"start": 30000, "end": 60000}},
+        {"topic": "S2", "key": 0, "value": "0,2000", "timestamp": 40000, "window": {"start": 30000, "end": 60000}}
 
       ]
     },
@@ -49,10 +49,10 @@
       ],
       "outputs": [
         {"topic": "S2", "key": 0, "value": "0,0", "timestamp": 0, "window": {"start": 0, "end": 30000}},
-        {"topic": "S2", "key": 0, "value": "0,0", "timestamp": 0, "window": {"start": 0, "end": 30000}},
+        {"topic": "S2", "key": 0, "value": "0,0", "timestamp": 10000, "window": {"start": 0, "end": 30000}},
         {"topic": "S2", "key": 100, "value": "100,100", "timestamp": 30000, "window": {"start": 30000, "end": 60000}},
-        {"topic": "S2", "key": 100, "value": "100,6", "timestamp": 30000, "window": {"start": 30000, "end": 60000}},
-        {"topic": "S2", "key": 100, "value": "100,6", "timestamp": 30000, "window": {"start": 30000, "end": 60000}}
+        {"topic": "S2", "key": 100, "value": "100,6", "timestamp": 45000, "window": {"start": 30000, "end": 60000}},
+        {"topic": "S2", "key": 100, "value": "100,6", "timestamp": 50000, "window": {"start": 30000, "end": 60000}}
       ]
     },
     {