diff --git a/source/MongoDB/Util/JsonFormatter.cs b/source/MongoDB/Util/JsonFormatter.cs
index 0d7daa40..23fad5b4 100644
--- a/source/MongoDB/Util/JsonFormatter.cs
+++ b/source/MongoDB/Util/JsonFormatter.cs
@@ -44,7 +44,7 @@ public static string SerializeForServerSide(object value)
             if (value is DateTime)
             {
                 DateTime d = (DateTime)value;
-                sb.AppendFormat("new Date({0},{1},{2},{3},{4},{5},{6})", d.Year, d.Month, d.Date, d.Hour, d.Minute, d.Second, d.Millisecond);
+                sb.AppendFormat("new Date({0},{1},{2},{3},{4},{5},{6})", d.Year, d.Month, d.Day, d.Hour, d.Minute, d.Second, d.Millisecond);
             }
             else
                 SerializeType(value, sb);