diff --git a/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/JSON.mustache b/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/JSON.mustache
index 06f26da304b..10a377ebb5a 100644
--- a/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/JSON.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/JSON.mustache
@@ -172,14 +172,15 @@ class DateAdapter implements JsonSerializer<Date>, JsonDeserializer<Date> {
  */
 class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
 
-    private final DateTimeFormatter formatter = ISODateTimeFormat.dateTime();
+    private final DateTimeFormatter parseFormatter = ISODateTimeFormat.dateOptionalTimeParser();
+    private final DateTimeFormatter printFormatter = ISODateTimeFormat.dateTime();
 
     @Override
     public void write(JsonWriter out, DateTime date) throws IOException {
         if (date == null) {
             out.nullValue();
         } else {
-            out.value(formatter.print(date));
+            out.value(printFormatter.print(date));
         }
     }
 
@@ -191,7 +192,7 @@ class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
                 return null;
             default:
                 String date = in.nextString();
-                return formatter.parseDateTime(date);
+                return parseFormatter.parseDateTime(date);
         }
     }
 }
diff --git a/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit/ApiClient.mustache b/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit/ApiClient.mustache
index ffbf93a48b4..6e987c5e14d 100644
--- a/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit/ApiClient.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit/ApiClient.mustache
@@ -354,14 +354,15 @@ class GsonConverterWrapper implements Converter {
  */
 class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
 
-    private final DateTimeFormatter formatter = ISODateTimeFormat.dateTime();
+    private final DateTimeFormatter parseFormatter = ISODateTimeFormat.dateOptionalTimeParser();
+    private final DateTimeFormatter printFormatter = ISODateTimeFormat.dateTime();
 
     @Override
     public void write(JsonWriter out, DateTime date) throws IOException {
         if (date == null) {
             out.nullValue();
         } else {
-            out.value(formatter.print(date));
+            out.value(printFormatter.print(date));
         }
     }
 
@@ -373,7 +374,7 @@ class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
                 return null;
             default:
                 String date = in.nextString();
-                return formatter.parseDateTime(date);
+                return parseFormatter.parseDateTime(date);
         }
     }
 }
diff --git a/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit2/ApiClient.mustache b/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit2/ApiClient.mustache
index f9434978704..7d4f106a05a 100644
--- a/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit2/ApiClient.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit2/ApiClient.mustache
@@ -374,14 +374,15 @@ class GsonCustomConverterFactory extends Converter.Factory
  */
 class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
 
-    private final DateTimeFormatter formatter = ISODateTimeFormat.dateTime();
+    private final DateTimeFormatter parseFormatter = ISODateTimeFormat.dateOptionalTimeParser();
+    private final DateTimeFormatter printFormatter = ISODateTimeFormat.dateTime();
 
     @Override
     public void write(JsonWriter out, DateTime date) throws IOException {
         if (date == null) {
             out.nullValue();
         } else {
-            out.value(formatter.print(date));
+            out.value(printFormatter.print(date));
         }
     }
 
@@ -393,7 +394,7 @@ class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
                 return null;
             default:
                 String date = in.nextString();
-                return formatter.parseDateTime(date);
+                return parseFormatter.parseDateTime(date);
         }
     }
 }
diff --git a/modules/swagger-codegen/src/main/resources/akka-scala/apiInvoker.mustache b/modules/swagger-codegen/src/main/resources/akka-scala/apiInvoker.mustache
index 3b8c6ec5fe3..6267b425ba1 100644
--- a/modules/swagger-codegen/src/main/resources/akka-scala/apiInvoker.mustache
+++ b/modules/swagger-codegen/src/main/resources/akka-scala/apiInvoker.mustache
@@ -85,10 +85,10 @@ object ApiInvoker {
 
   case object DateTimeSerializer extends CustomSerializer[DateTime](format => ( {
     case JString(s) =>
-      ISODateTimeFormat.dateTimeParser().parseDateTime(s)
+      ISODateTimeFormat.dateOptionalTimeParser().parseDateTime(s)
   }, {
     case d: DateTime =>
-      JString(ISODateTimeFormat.dateTimeParser().print(d))
+      JString(ISODateTimeFormat.dateTime().print(d))
   }))
 }
 
diff --git a/samples/client/petstore-security-test/java/okhttp-gson/src/main/java/io/swagger/client/JSON.java b/samples/client/petstore-security-test/java/okhttp-gson/src/main/java/io/swagger/client/JSON.java
index 4ff3984453d..43b8be5d60c 100644
--- a/samples/client/petstore-security-test/java/okhttp-gson/src/main/java/io/swagger/client/JSON.java
+++ b/samples/client/petstore-security-test/java/okhttp-gson/src/main/java/io/swagger/client/JSON.java
@@ -170,14 +170,15 @@ class DateAdapter implements JsonSerializer<Date>, JsonDeserializer<Date> {
  */
 class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
 
-    private final DateTimeFormatter formatter = ISODateTimeFormat.dateTime();
+    private final DateTimeFormatter parseFormatter = ISODateTimeFormat.dateOptionalTimeParser();
+    private final DateTimeFormatter printFormatter = ISODateTimeFormat.dateTime();
 
     @Override
     public void write(JsonWriter out, DateTime date) throws IOException {
         if (date == null) {
             out.nullValue();
         } else {
-            out.value(formatter.print(date));
+            out.value(printFormatter.print(date));
         }
     }
 
@@ -189,7 +190,7 @@ class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
                 return null;
             default:
                 String date = in.nextString();
-                return formatter.parseDateTime(date);
+                return parseFormatter.parseDateTime(date);
         }
     }
 }
diff --git a/samples/client/petstore/akka-scala/src/main/scala/io/swagger/client/core/ApiInvoker.scala b/samples/client/petstore/akka-scala/src/main/scala/io/swagger/client/core/ApiInvoker.scala
index 18505facbd8..73949422393 100644
--- a/samples/client/petstore/akka-scala/src/main/scala/io/swagger/client/core/ApiInvoker.scala
+++ b/samples/client/petstore/akka-scala/src/main/scala/io/swagger/client/core/ApiInvoker.scala
@@ -85,10 +85,10 @@ object ApiInvoker {
 
   case object DateTimeSerializer extends CustomSerializer[DateTime](format => ( {
     case JString(s) =>
-      ISODateTimeFormat.dateTimeParser().parseDateTime(s)
+      ISODateTimeFormat.dateOptionalTimeParser().parseDateTime(s)
   }, {
     case d: DateTime =>
-      JString(ISODateTimeFormat.dateTimeParser().print(d))
+      JString(ISODateTimeFormat.dateTime().print(d))
   }))
 }
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/io/swagger/client/JSON.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/io/swagger/client/JSON.java
index a734bec47f1..0445a969c0a 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/io/swagger/client/JSON.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/io/swagger/client/JSON.java
@@ -182,14 +182,15 @@ class DateAdapter implements JsonSerializer<Date>, JsonDeserializer<Date> {
  */
 class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
 
-    private final DateTimeFormatter formatter = ISODateTimeFormat.dateTime();
+    private final DateTimeFormatter parseFormatter = ISODateTimeFormat.dateOptionalTimeParser();
+    private final DateTimeFormatter printFormatter = ISODateTimeFormat.dateTime();
 
     @Override
     public void write(JsonWriter out, DateTime date) throws IOException {
         if (date == null) {
             out.nullValue();
         } else {
-            out.value(formatter.print(date));
+            out.value(printFormatter.print(date));
         }
     }
 
@@ -201,7 +202,7 @@ class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
                 return null;
             default:
                 String date = in.nextString();
-                return formatter.parseDateTime(date);
+                return parseFormatter.parseDateTime(date);
         }
     }
 }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/JSON.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/JSON.java
index 5692584772f..d72b38c9568 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/JSON.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/JSON.java
@@ -170,14 +170,15 @@ class DateAdapter implements JsonSerializer<Date>, JsonDeserializer<Date> {
  */
 class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
 
-    private final DateTimeFormatter formatter = ISODateTimeFormat.dateTime();
+    private final DateTimeFormatter parseFormatter = ISODateTimeFormat.dateOptionalTimeParser();
+    private final DateTimeFormatter printFormatter = ISODateTimeFormat.dateTime();
 
     @Override
     public void write(JsonWriter out, DateTime date) throws IOException {
         if (date == null) {
             out.nullValue();
         } else {
-            out.value(formatter.print(date));
+            out.value(printFormatter.print(date));
         }
     }
 
@@ -189,7 +190,7 @@ class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
                 return null;
             default:
                 String date = in.nextString();
-                return formatter.parseDateTime(date);
+                return parseFormatter.parseDateTime(date);
         }
     }
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/ApiClient.java b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/ApiClient.java
index be9eadc33ba..6bd0aac79ab 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/ApiClient.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/ApiClient.java
@@ -362,14 +362,15 @@ class GsonCustomConverterFactory extends Converter.Factory
  */
 class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
 
-    private final DateTimeFormatter formatter = ISODateTimeFormat.dateTime();
+    private final DateTimeFormatter parseFormatter = ISODateTimeFormat.dateOptionalTimeParser();
+    private final DateTimeFormatter printFormatter = ISODateTimeFormat.dateTime();
 
     @Override
     public void write(JsonWriter out, DateTime date) throws IOException {
         if (date == null) {
             out.nullValue();
         } else {
-            out.value(formatter.print(date));
+            out.value(printFormatter.print(date));
         }
     }
 
@@ -381,7 +382,7 @@ class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
                 return null;
             default:
                 String date = in.nextString();
-                return formatter.parseDateTime(date);
+                return parseFormatter.parseDateTime(date);
         }
     }
 }
diff --git a/samples/client/petstore/java/retrofit2rx/src/main/java/io/swagger/client/ApiClient.java b/samples/client/petstore/java/retrofit2rx/src/main/java/io/swagger/client/ApiClient.java
index cc82b88c425..d3eb060514f 100644
--- a/samples/client/petstore/java/retrofit2rx/src/main/java/io/swagger/client/ApiClient.java
+++ b/samples/client/petstore/java/retrofit2rx/src/main/java/io/swagger/client/ApiClient.java
@@ -362,14 +362,15 @@ class GsonCustomConverterFactory extends Converter.Factory
  */
 class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
 
-    private final DateTimeFormatter formatter = ISODateTimeFormat.dateTime();
+    private final DateTimeFormatter parseFormatter = ISODateTimeFormat.dateOptionalTimeParser();
+    private final DateTimeFormatter printFormatter = ISODateTimeFormat.dateTime();
 
     @Override
     public void write(JsonWriter out, DateTime date) throws IOException {
         if (date == null) {
             out.nullValue();
         } else {
-            out.value(formatter.print(date));
+            out.value(printFormatter.print(date));
         }
     }
 
@@ -381,7 +382,7 @@ class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
                 return null;
             default:
                 String date = in.nextString();
-                return formatter.parseDateTime(date);
+                return parseFormatter.parseDateTime(date);
         }
     }
 }