diff --git a/modules/swagger-codegen/src/main/resources/Java/ApiClient.mustache b/modules/swagger-codegen/src/main/resources/Java/ApiClient.mustache
index c81b75d73db..91d1eb93daf 100644
--- a/modules/swagger-codegen/src/main/resources/Java/ApiClient.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/ApiClient.mustache
@@ -55,13 +55,15 @@ public class ApiClient {
   private DateFormat dateFormat;
 
   public ApiClient() {
-    // Use ISO 8601 format for date and datetime.
-    // See https://en.wikipedia.org/wiki/ISO_8601
-    this.dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
+    // Use RFC3339 format for date and datetime.
+    // See http://xml2rfc.ietf.org/public/rfc/html/rfc3339.html#anchor14
+    this.dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
 
     // Use UTC as the default time zone.
     this.dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
 
+    this.json.setDateFormat((DateFormat) dateFormat.clone());
+
     // Set default User-Agent.
     setUserAgent("Java-Swagger");
 
@@ -74,6 +76,13 @@ public class ApiClient {
     authentications = Collections.unmodifiableMap(authentications);
   }
 
+  /**
+   * Gets the JSON instance to do JSON serialization and deserialization.
+   */
+  public JSON getJSON() {
+    return json;
+  }
+
   public String getBasePath() {
     return basePath;
   }
@@ -227,6 +236,8 @@ public class ApiClient {
    */
   public ApiClient setDateFormat(DateFormat dateFormat) {
     this.dateFormat = dateFormat;
+    // also set the date format for model (de)serialization with Date properties
+    this.json.setDateFormat((DateFormat) dateFormat.clone());
     return this;
   }
 
diff --git a/modules/swagger-codegen/src/main/resources/Java/JSON.mustache b/modules/swagger-codegen/src/main/resources/Java/JSON.mustache
index 43b38f6e21d..54faed8dcb3 100644
--- a/modules/swagger-codegen/src/main/resources/Java/JSON.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/JSON.mustache
@@ -4,6 +4,8 @@ import com.fasterxml.jackson.annotation.*;
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.datatype.joda.*;
 
+import java.text.DateFormat;
+
 import java.io.IOException;
 
 {{>generatedAnnotation}}
@@ -20,6 +22,13 @@ public class JSON {
     mapper.registerModule(new JodaModule());
   }
 
+  /**
+   * Set the date format for JSON (de)serialization with Date properties.
+   */
+  public void setDateFormat(DateFormat dateFormat) {
+    mapper.setDateFormat(dateFormat);
+  }
+
   /**
    * Serialize the given Java object into JSON string.
    */
diff --git a/modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/ApiClient.mustache b/modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/ApiClient.mustache
index c71b6089358..bd64a6fe659 100644
--- a/modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/ApiClient.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/ApiClient.mustache
@@ -60,13 +60,15 @@ public class ApiClient {
   private DateFormat dateFormat;
 
   public ApiClient() {
-    // Use ISO 8601 format for date and datetime.
-    // See https://en.wikipedia.org/wiki/ISO_8601
-    this.dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
+    // Use RFC3339 format for date and datetime.
+    // See http://xml2rfc.ietf.org/public/rfc/html/rfc3339.html#anchor14
+    this.dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
 
     // Use UTC as the default time zone.
     this.dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
 
+    this.json.setDateFormat((DateFormat) dateFormat.clone());
+
     // Set default User-Agent.
     setUserAgent("Java-Swagger");
 
@@ -81,6 +83,13 @@ public class ApiClient {
     authentications = Collections.unmodifiableMap(authentications);
   }
 
+  /**
+   * Gets the JSON instance to do JSON serialization and deserialization.
+   */
+  public JSON getJSON() {
+    return json;
+  }
+
   public String getBasePath() {
     return basePath;
   }
@@ -235,6 +244,8 @@ public class ApiClient {
    */
   public ApiClient setDateFormat(DateFormat dateFormat) {
     this.dateFormat = dateFormat;
+    // also set the date format for model (de)serialization with Date properties
+    this.json.setDateFormat((DateFormat) dateFormat.clone());
     return this;
   }
 
diff --git a/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/ApiClient.mustache b/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/ApiClient.mustache
index 2ee5ab3e887..f238c37fb47 100644
--- a/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/ApiClient.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/ApiClient.mustache
@@ -75,13 +75,11 @@ public class ApiClient {
   private int statusCode;
   private Map<String, List<String>> responseHeaders;
 
-  private String dateFormat;
-  private DateFormat dateFormatter;
+  private DateFormat dateFormat;
+  private DateFormat datetimeFormat;
+  private boolean lenientDatetimeFormat;
   private int dateLength;
 
-  private String datetimeFormat;
-  private DateFormat datetimeFormatter;
-
   private InputStream sslCaCert;
   private boolean verifyingSsl;
 
@@ -95,10 +93,19 @@ public class ApiClient {
 
     json = new JSON(this);
 
-    // Use ISO 8601 format for date and datetime.
-    // See https://en.wikipedia.org/wiki/ISO_8601
-    setDateFormat("yyyy-MM-dd");
-    setDatetimeFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
+    /*
+     * Use RFC3339 format for date and datetime.
+     * See http://xml2rfc.ietf.org/public/rfc/html/rfc3339.html#anchor14
+     */
+    this.dateFormat = new SimpleDateFormat("yyyy-MM-dd");
+    // Always use UTC as the default time zone when dealing with date (without time).
+    this.dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
+    // Use the system's default time zone when dealing with datetime (mainly formatting).
+    this.datetimeFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
+
+    // Be lenient on datetime formats when parsing datetime from string.
+    // See <code>parseDatetime</code>.
+    this.lenientDatetimeFormat = true;
 
     // Set default User-Agent.
     setUserAgent("Java-Swagger");
@@ -186,32 +193,35 @@ public class ApiClient {
     return this;
   }
 
-  public String getDateFormat() {
+  public DateFormat getDateFormat() {
     return dateFormat;
   }
 
-  public ApiClient setDateFormat(String dateFormat) {
+  public ApiClient setDateFormat(DateFormat dateFormat) {
     this.dateFormat = dateFormat;
-
-    this.dateFormatter = new SimpleDateFormat(dateFormat);
-    // Use UTC as the default time zone.
-    this.dateFormatter.setTimeZone(TimeZone.getTimeZone("UTC"));
-
-    this.dateLength = this.dateFormatter.format(new Date()).length();
-
+    this.dateLength = this.dateFormat.format(new Date()).length();
     return this;
   }
 
-  public String getDatetimeFormat() {
+  public DateFormat getDatetimeFormat() {
     return datetimeFormat;
   }
 
-  public ApiClient setDatetimeFormat(String datetimeFormat) {
+  public ApiClient setDatetimeFormat(DateFormat datetimeFormat) {
     this.datetimeFormat = datetimeFormat;
+    return this;
+  }
 
-    this.datetimeFormatter = new SimpleDateFormat(datetimeFormat);
-    // Note: The datetime formatter uses the system's default time zone.
+  /**
+   * Whether to allow various ISO 8601 datetime formats when parsing a datetime string.
+   * @see #parseDatetime(String)
+   */
+  public boolean isLenientDatetimeFormat() {
+    return lenientDatetimeFormat;
+  }
 
+  public ApiClient setLenientDatetimeFormat(boolean lenientDatetimeFormat) {
+    this.lenientDatetimeFormat = lenientDatetimeFormat;
     return this;
   }
 
@@ -225,15 +235,15 @@ public class ApiClient {
     if (str == null)
       return null;
     try {
-      return dateFormatter.parse(str);
+      return dateFormat.parse(str);
     } catch (ParseException e) {
       throw new RuntimeException(e);
     }
   }
 
   /**
-   * Parse the given date-time string into Date object.
-   * The default <code>datetimeFormat</code> supports these ISO 8601 datetime formats:
+   * Parse the given datetime string into Date object.
+   * When <code>lenientDatetimeFormat</code> is enabled, the following ISO 8601 datetime formats are supported:
    *   2015-08-16T08:20:05Z
    *   2015-8-16T8:20:05Z
    *   2015-08-16T08:20:05+00:00
@@ -253,25 +263,25 @@ public class ApiClient {
     if (str == null)
       return null;
 
-    if ("yyyy-MM-dd'T'HH:mm:ss.SSSZ".equals(datetimeFormat)) {
+    if (lenientDatetimeFormat) {
       /*
-       * When the default datetime format is used, process the given string
+       * When lenientDatetimeFormat is enabled, process the given string
        * to support various formats defined by ISO 8601.
        */
       // normalize time zone
-      //   trailing "Z": 2015-08-16T08:20:05Z => 2015-08-16T08:20:05+0000
-      str = str.replaceAll("[zZ]\\z", "+0000");
-      //   remove colon: 2015-08-16T08:20:05+00:00 => 2015-08-16T08:20:05+0000
-      str = str.replaceAll("([+-]\\d{2}):(\\d{2})\\z", "$1$2");
-      //   expand time zone: 2015-08-16T08:20:05+00 => 2015-08-16T08:20:05+0000
-      str = str.replaceAll("([+-]\\d{2})\\z", "$100");
+      //   trailing "Z": 2015-08-16T08:20:05Z => 2015-08-16T08:20:05+00:00
+      str = str.replaceAll("[zZ]\\z", "+00:00");
+      //   add colon: 2015-08-16T08:20:05+0000 => 2015-08-16T08:20:05+00:00
+      str = str.replaceAll("([+-]\\d{2})(\\d{2})\\z", "$1:$2");
+      //   expand time zone: 2015-08-16T08:20:05+00 => 2015-08-16T08:20:05+00:00
+      str = str.replaceAll("([+-]\\d{2})\\z", "$1:00");
       // add milliseconds when missing
-      //   2015-08-16T08:20:05+0000 => 2015-08-16T08:20:05.000+0000
-      str = str.replaceAll("(:\\d{1,2})([+-]\\d{4})\\z", "$1.000$2");
+      //   2015-08-16T08:20:05+00:00 => 2015-08-16T08:20:05.000+00:00
+      str = str.replaceAll("(:\\d{1,2})([+-]\\d{2}:\\d{2})\\z", "$1.000$2");
     }
 
     try {
-      return datetimeFormatter.parse(str);
+      return datetimeFormat.parse(str);
     } catch (ParseException e) {
       throw new RuntimeException(e);
     }
@@ -290,14 +300,14 @@ public class ApiClient {
    * Format the given Date object into string.
    */
   public String formatDate(Date date) {
-    return dateFormatter.format(date);
+    return dateFormat.format(date);
   }
 
   /**
    * Format the given Date object into string.
    */
   public String formatDatetime(Date date) {
-    return datetimeFormatter.format(date);
+    return datetimeFormat.format(date);
   }
 
   /**
diff --git a/samples/client/petstore/java/default/src/main/java/io/swagger/client/ApiClient.java b/samples/client/petstore/java/default/src/main/java/io/swagger/client/ApiClient.java
index da7f3ba5a4e..bb8aaa7b990 100644
--- a/samples/client/petstore/java/default/src/main/java/io/swagger/client/ApiClient.java
+++ b/samples/client/petstore/java/default/src/main/java/io/swagger/client/ApiClient.java
@@ -39,7 +39,7 @@ import io.swagger.client.auth.HttpBasicAuth;
 import io.swagger.client.auth.ApiKeyAuth;
 import io.swagger.client.auth.OAuth;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-02T21:16:46.418+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-07T15:05:10.376+08:00")
 public class ApiClient {
   private Map<String, Client> hostMap = new HashMap<String, Client>();
   private Map<String, String> defaultHeaderMap = new HashMap<String, String>();
@@ -55,13 +55,15 @@ public class ApiClient {
   private DateFormat dateFormat;
 
   public ApiClient() {
-    // Use ISO 8601 format for date and datetime.
-    // See https://en.wikipedia.org/wiki/ISO_8601
-    this.dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
+    // Use RFC3339 format for date and datetime.
+    // See http://xml2rfc.ietf.org/public/rfc/html/rfc3339.html#anchor14
+    this.dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
 
     // Use UTC as the default time zone.
     this.dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
 
+    this.json.setDateFormat((DateFormat) dateFormat.clone());
+
     // Set default User-Agent.
     setUserAgent("Java-Swagger");
 
@@ -73,6 +75,13 @@ public class ApiClient {
     authentications = Collections.unmodifiableMap(authentications);
   }
 
+  /**
+   * Gets the JSON instance to do JSON serialization and deserialization.
+   */
+  public JSON getJSON() {
+    return json;
+  }
+
   public String getBasePath() {
     return basePath;
   }
@@ -226,6 +235,8 @@ public class ApiClient {
    */
   public ApiClient setDateFormat(DateFormat dateFormat) {
     this.dateFormat = dateFormat;
+    // also set the date format for model (de)serialization with Date properties
+    this.json.setDateFormat((DateFormat) dateFormat.clone());
     return this;
   }
 
diff --git a/samples/client/petstore/java/default/src/main/java/io/swagger/client/JSON.java b/samples/client/petstore/java/default/src/main/java/io/swagger/client/JSON.java
index 60872714a37..180f9b8cc19 100644
--- a/samples/client/petstore/java/default/src/main/java/io/swagger/client/JSON.java
+++ b/samples/client/petstore/java/default/src/main/java/io/swagger/client/JSON.java
@@ -4,9 +4,11 @@ import com.fasterxml.jackson.annotation.*;
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.datatype.joda.*;
 
+import java.text.DateFormat;
+
 import java.io.IOException;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-10-30T16:36:47.681+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-07T15:05:10.376+08:00")
 public class JSON {
   private ObjectMapper mapper;
 
@@ -20,6 +22,13 @@ public class JSON {
     mapper.registerModule(new JodaModule());
   }
 
+  /**
+   * Set the date format for JSON (de)serialization with Date properties.
+   */
+  public void setDateFormat(DateFormat dateFormat) {
+    mapper.setDateFormat(dateFormat);
+  }
+
   /**
    * Serialize the given Java object into JSON string.
    */
diff --git a/samples/client/petstore/java/default/src/test/java/io/swagger/client/ApiClientTest.java b/samples/client/petstore/java/default/src/test/java/io/swagger/client/ApiClientTest.java
index 802c0cae3b9..3d57f3fa84c 100644
--- a/samples/client/petstore/java/default/src/test/java/io/swagger/client/ApiClientTest.java
+++ b/samples/client/petstore/java/default/src/test/java/io/swagger/client/ApiClientTest.java
@@ -2,6 +2,8 @@ package io.swagger.client;
 
 import io.swagger.client.auth.*;
 
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
 import java.util.*;
 
 import org.junit.*;
@@ -16,6 +18,26 @@ public class ApiClientTest {
         apiClient = new ApiClient();
     }
 
+    @Test
+    public void testParseAndFormatDate() {
+        // default date format
+        String dateStr = "2015-11-07T03:49:09.356Z";
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T03:49:09.356+00:00")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T03:49:09.356Z")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T05:49:09.356+02:00")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T02:49:09.356-01:00")));
+
+        // custom date format: without milli-seconds, custom time zone
+        DateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssXXX");
+        format.setTimeZone(TimeZone.getTimeZone("GMT+10"));
+        apiClient.setDateFormat(format);
+        dateStr = "2015-11-07T13:49:09+10:00";
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T03:49:09+00:00")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T03:49:09Z")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T00:49:09-03:00")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T13:49:09+10:00")));
+    }
+
     @Test
     public void testSelectHeaderAccept() {
         String[] accepts = {"APPLICATION/JSON", "APPLICATION/XML"};
diff --git a/samples/client/petstore/java/default/src/test/java/io/swagger/client/JSONTest.java b/samples/client/petstore/java/default/src/test/java/io/swagger/client/JSONTest.java
new file mode 100644
index 00000000000..1250a135078
--- /dev/null
+++ b/samples/client/petstore/java/default/src/test/java/io/swagger/client/JSONTest.java
@@ -0,0 +1,52 @@
+package io.swagger.client;
+
+import io.swagger.client.model.Order;
+
+import java.lang.Exception;
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.*;
+import java.util.TimeZone;
+
+import org.junit.*;
+import static org.junit.Assert.*;
+
+
+public class JSONTest {
+    JSON json = null;
+    Order order = null;
+
+    @Before
+    public void setup() {
+        json = new JSON();
+        order = new Order();
+    }
+
+    @Test
+    public void testDefaultDate() throws Exception {
+        final DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
+        dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
+        final String dateStr = "2015-11-07T14:11:05.267Z";
+        order.setShipDate(dateFormat.parse(dateStr));
+
+        String str = json.serialize(order);
+        TypeRef typeRef = new TypeRef<Order>() { };
+        Order o = json.deserialize(str, typeRef);
+        assertEquals(dateStr, dateFormat.format(o.getShipDate()));
+    }
+
+    @Test
+    public void testCustomDate() throws Exception {
+        final DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssXXX");
+        dateFormat.setTimeZone(TimeZone.getTimeZone("GMT-2"));
+        final String dateStr = "2015-11-07T14:11:05-02:00";
+        order.setShipDate(dateFormat.parse(dateStr));
+
+        json.setDateFormat(dateFormat);
+        String str = json.serialize(order);
+        TypeRef typeRef = new TypeRef<Order>() { };
+        Order o = json.deserialize(str, typeRef);
+        assertEquals(dateStr, dateFormat.format(o.getShipDate()));
+    }
+}
\ No newline at end of file
diff --git a/samples/client/petstore/java/default/src/test/java/io/swagger/petstore/test/StoreApiTest.java b/samples/client/petstore/java/default/src/test/java/io/swagger/petstore/test/StoreApiTest.java
index a1fd7e345a8..6094f2242e1 100644
--- a/samples/client/petstore/java/default/src/test/java/io/swagger/petstore/test/StoreApiTest.java
+++ b/samples/client/petstore/java/default/src/test/java/io/swagger/petstore/test/StoreApiTest.java
@@ -8,6 +8,7 @@ import io.swagger.client.auth.*;
 import io.swagger.client.model.*;
 
 import java.util.Map;
+import java.text.SimpleDateFormat;
 
 import org.junit.*;
 import static org.junit.Assert.*;
@@ -21,6 +22,8 @@ public class StoreApiTest {
         // setup authentication
         ApiKeyAuth apiKeyAuth = (ApiKeyAuth) api.getApiClient().getAuthentication("api_key");
         apiKeyAuth.setApiKey("special-key");
+        // set custom date format that is used by the petstore server
+        api.getApiClient().setDateFormat(new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ"));
     }
 
     @Test
diff --git a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/ApiClient.java b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/ApiClient.java
index 1fc3258b9dc..9bbc5407af0 100644
--- a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/ApiClient.java
+++ b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/ApiClient.java
@@ -43,7 +43,7 @@ import io.swagger.client.auth.HttpBasicAuth;
 import io.swagger.client.auth.ApiKeyAuth;
 import io.swagger.client.auth.OAuth;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-02T22:10:35.641+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-09T11:02:32.553+08:00")
 public class ApiClient {
   private Client client;
   private Map<String, Client> hostMap = new HashMap<String, Client>();
@@ -60,13 +60,15 @@ public class ApiClient {
   private DateFormat dateFormat;
 
   public ApiClient() {
-    // Use ISO 8601 format for date and datetime.
-    // See https://en.wikipedia.org/wiki/ISO_8601
-    this.dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
+    // Use RFC3339 format for date and datetime.
+    // See http://xml2rfc.ietf.org/public/rfc/html/rfc3339.html#anchor14
+    this.dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
 
     // Use UTC as the default time zone.
     this.dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
 
+    this.json.setDateFormat((DateFormat) dateFormat.clone());
+
     // Set default User-Agent.
     setUserAgent("Java-Swagger");
 
@@ -80,6 +82,13 @@ public class ApiClient {
     authentications = Collections.unmodifiableMap(authentications);
   }
 
+  /**
+   * Gets the JSON instance to do JSON serialization and deserialization.
+   */
+  public JSON getJSON() {
+    return json;
+  }
+
   public String getBasePath() {
     return basePath;
   }
@@ -234,6 +243,8 @@ public class ApiClient {
    */
   public ApiClient setDateFormat(DateFormat dateFormat) {
     this.dateFormat = dateFormat;
+    // also set the date format for model (de)serialization with Date properties
+    this.json.setDateFormat((DateFormat) dateFormat.clone());
     return this;
   }
 
diff --git a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/JSON.java b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/JSON.java
index 8ce930ce5c1..35ab10fd9c6 100644
--- a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/JSON.java
+++ b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/JSON.java
@@ -4,9 +4,11 @@ import com.fasterxml.jackson.annotation.*;
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.datatype.joda.*;
 
+import java.text.DateFormat;
+
 import java.io.IOException;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-10-21T11:55:20.020+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-09T11:02:32.553+08:00")
 public class JSON {
   private ObjectMapper mapper;
 
@@ -20,6 +22,13 @@ public class JSON {
     mapper.registerModule(new JodaModule());
   }
 
+  /**
+   * Set the date format for JSON (de)serialization with Date properties.
+   */
+  public void setDateFormat(DateFormat dateFormat) {
+    mapper.setDateFormat(dateFormat);
+  }
+
   /**
    * Serialize the given Java object into JSON string.
    */
diff --git a/samples/client/petstore/java/jersey2/src/test/java/io/swagger/client/ApiClientTest.java b/samples/client/petstore/java/jersey2/src/test/java/io/swagger/client/ApiClientTest.java
index 802c0cae3b9..3d57f3fa84c 100644
--- a/samples/client/petstore/java/jersey2/src/test/java/io/swagger/client/ApiClientTest.java
+++ b/samples/client/petstore/java/jersey2/src/test/java/io/swagger/client/ApiClientTest.java
@@ -2,6 +2,8 @@ package io.swagger.client;
 
 import io.swagger.client.auth.*;
 
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
 import java.util.*;
 
 import org.junit.*;
@@ -16,6 +18,26 @@ public class ApiClientTest {
         apiClient = new ApiClient();
     }
 
+    @Test
+    public void testParseAndFormatDate() {
+        // default date format
+        String dateStr = "2015-11-07T03:49:09.356Z";
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T03:49:09.356+00:00")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T03:49:09.356Z")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T05:49:09.356+02:00")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T02:49:09.356-01:00")));
+
+        // custom date format: without milli-seconds, custom time zone
+        DateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssXXX");
+        format.setTimeZone(TimeZone.getTimeZone("GMT+10"));
+        apiClient.setDateFormat(format);
+        dateStr = "2015-11-07T13:49:09+10:00";
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T03:49:09+00:00")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T03:49:09Z")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T00:49:09-03:00")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07T13:49:09+10:00")));
+    }
+
     @Test
     public void testSelectHeaderAccept() {
         String[] accepts = {"APPLICATION/JSON", "APPLICATION/XML"};
diff --git a/samples/client/petstore/java/jersey2/src/test/java/io/swagger/client/JSONTest.java b/samples/client/petstore/java/jersey2/src/test/java/io/swagger/client/JSONTest.java
new file mode 100644
index 00000000000..1250a135078
--- /dev/null
+++ b/samples/client/petstore/java/jersey2/src/test/java/io/swagger/client/JSONTest.java
@@ -0,0 +1,52 @@
+package io.swagger.client;
+
+import io.swagger.client.model.Order;
+
+import java.lang.Exception;
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.*;
+import java.util.TimeZone;
+
+import org.junit.*;
+import static org.junit.Assert.*;
+
+
+public class JSONTest {
+    JSON json = null;
+    Order order = null;
+
+    @Before
+    public void setup() {
+        json = new JSON();
+        order = new Order();
+    }
+
+    @Test
+    public void testDefaultDate() throws Exception {
+        final DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
+        dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
+        final String dateStr = "2015-11-07T14:11:05.267Z";
+        order.setShipDate(dateFormat.parse(dateStr));
+
+        String str = json.serialize(order);
+        TypeRef typeRef = new TypeRef<Order>() { };
+        Order o = json.deserialize(str, typeRef);
+        assertEquals(dateStr, dateFormat.format(o.getShipDate()));
+    }
+
+    @Test
+    public void testCustomDate() throws Exception {
+        final DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssXXX");
+        dateFormat.setTimeZone(TimeZone.getTimeZone("GMT-2"));
+        final String dateStr = "2015-11-07T14:11:05-02:00";
+        order.setShipDate(dateFormat.parse(dateStr));
+
+        json.setDateFormat(dateFormat);
+        String str = json.serialize(order);
+        TypeRef typeRef = new TypeRef<Order>() { };
+        Order o = json.deserialize(str, typeRef);
+        assertEquals(dateStr, dateFormat.format(o.getShipDate()));
+    }
+}
\ No newline at end of file
diff --git a/samples/client/petstore/java/jersey2/src/test/java/io/swagger/petstore/test/StoreApiTest.java b/samples/client/petstore/java/jersey2/src/test/java/io/swagger/petstore/test/StoreApiTest.java
index a1fd7e345a8..6094f2242e1 100644
--- a/samples/client/petstore/java/jersey2/src/test/java/io/swagger/petstore/test/StoreApiTest.java
+++ b/samples/client/petstore/java/jersey2/src/test/java/io/swagger/petstore/test/StoreApiTest.java
@@ -8,6 +8,7 @@ import io.swagger.client.auth.*;
 import io.swagger.client.model.*;
 
 import java.util.Map;
+import java.text.SimpleDateFormat;
 
 import org.junit.*;
 import static org.junit.Assert.*;
@@ -21,6 +22,8 @@ public class StoreApiTest {
         // setup authentication
         ApiKeyAuth apiKeyAuth = (ApiKeyAuth) api.getApiClient().getAuthentication("api_key");
         apiKeyAuth.setApiKey("special-key");
+        // set custom date format that is used by the petstore server
+        api.getApiClient().setDateFormat(new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ"));
     }
 
     @Test
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiClient.java
index 88b8f5602d1..51c3d5464f2 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiClient.java
@@ -75,13 +75,11 @@ public class ApiClient {
   private int statusCode;
   private Map<String, List<String>> responseHeaders;
 
-  private String dateFormat;
-  private DateFormat dateFormatter;
+  private DateFormat dateFormat;
+  private DateFormat datetimeFormat;
+  private boolean lenientDatetimeFormat;
   private int dateLength;
 
-  private String datetimeFormat;
-  private DateFormat datetimeFormatter;
-
   private InputStream sslCaCert;
   private boolean verifyingSsl;
 
@@ -95,10 +93,19 @@ public class ApiClient {
 
     json = new JSON(this);
 
-    // Use ISO 8601 format for date and datetime.
-    // See https://en.wikipedia.org/wiki/ISO_8601
-    setDateFormat("yyyy-MM-dd");
-    setDatetimeFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
+    /*
+     * Use RFC3339 format for date and datetime.
+     * See http://xml2rfc.ietf.org/public/rfc/html/rfc3339.html#anchor14
+     */
+    this.dateFormat = new SimpleDateFormat("yyyy-MM-dd");
+    // Always use UTC as the default time zone when dealing with date (without time).
+    this.dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
+    // Use the system's default time zone when dealing with datetime (mainly formatting).
+    this.datetimeFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
+
+    // Be lenient on datetime formats when parsing datetime from string.
+    // See <code>parseDatetime</code>.
+    this.lenientDatetimeFormat = true;
 
     // Set default User-Agent.
     setUserAgent("Java-Swagger");
@@ -185,32 +192,35 @@ public class ApiClient {
     return this;
   }
 
-  public String getDateFormat() {
+  public DateFormat getDateFormat() {
     return dateFormat;
   }
 
-  public ApiClient setDateFormat(String dateFormat) {
+  public ApiClient setDateFormat(DateFormat dateFormat) {
     this.dateFormat = dateFormat;
-
-    this.dateFormatter = new SimpleDateFormat(dateFormat);
-    // Use UTC as the default time zone.
-    this.dateFormatter.setTimeZone(TimeZone.getTimeZone("UTC"));
-
-    this.dateLength = this.dateFormatter.format(new Date()).length();
-
+    this.dateLength = this.dateFormat.format(new Date()).length();
     return this;
   }
 
-  public String getDatetimeFormat() {
+  public DateFormat getDatetimeFormat() {
     return datetimeFormat;
   }
 
-  public ApiClient setDatetimeFormat(String datetimeFormat) {
+  public ApiClient setDatetimeFormat(DateFormat datetimeFormat) {
     this.datetimeFormat = datetimeFormat;
+    return this;
+  }
 
-    this.datetimeFormatter = new SimpleDateFormat(datetimeFormat);
-    // Note: The datetime formatter uses the system's default time zone.
+  /**
+   * Whether to allow various ISO 8601 datetime formats when parsing a datetime string.
+   * @see #parseDatetime(String)
+   */
+  public boolean isLenientDatetimeFormat() {
+    return lenientDatetimeFormat;
+  }
 
+  public ApiClient setLenientDatetimeFormat(boolean lenientDatetimeFormat) {
+    this.lenientDatetimeFormat = lenientDatetimeFormat;
     return this;
   }
 
@@ -224,15 +234,15 @@ public class ApiClient {
     if (str == null)
       return null;
     try {
-      return dateFormatter.parse(str);
+      return dateFormat.parse(str);
     } catch (ParseException e) {
       throw new RuntimeException(e);
     }
   }
 
   /**
-   * Parse the given date-time string into Date object.
-   * The default <code>datetimeFormat</code> supports these ISO 8601 datetime formats:
+   * Parse the given datetime string into Date object.
+   * When <code>lenientDatetimeFormat</code> is enabled, the following ISO 8601 datetime formats are supported:
    *   2015-08-16T08:20:05Z
    *   2015-8-16T8:20:05Z
    *   2015-08-16T08:20:05+00:00
@@ -252,25 +262,25 @@ public class ApiClient {
     if (str == null)
       return null;
 
-    if ("yyyy-MM-dd'T'HH:mm:ss.SSSZ".equals(datetimeFormat)) {
+    if (lenientDatetimeFormat) {
       /*
-       * When the default datetime format is used, process the given string
+       * When lenientDatetimeFormat is enabled, process the given string
        * to support various formats defined by ISO 8601.
        */
       // normalize time zone
-      //   trailing "Z": 2015-08-16T08:20:05Z => 2015-08-16T08:20:05+0000
-      str = str.replaceAll("[zZ]\\z", "+0000");
-      //   remove colon: 2015-08-16T08:20:05+00:00 => 2015-08-16T08:20:05+0000
-      str = str.replaceAll("([+-]\\d{2}):(\\d{2})\\z", "$1$2");
-      //   expand time zone: 2015-08-16T08:20:05+00 => 2015-08-16T08:20:05+0000
-      str = str.replaceAll("([+-]\\d{2})\\z", "$100");
+      //   trailing "Z": 2015-08-16T08:20:05Z => 2015-08-16T08:20:05+00:00
+      str = str.replaceAll("[zZ]\\z", "+00:00");
+      //   add colon: 2015-08-16T08:20:05+0000 => 2015-08-16T08:20:05+00:00
+      str = str.replaceAll("([+-]\\d{2})(\\d{2})\\z", "$1:$2");
+      //   expand time zone: 2015-08-16T08:20:05+00 => 2015-08-16T08:20:05+00:00
+      str = str.replaceAll("([+-]\\d{2})\\z", "$1:00");
       // add milliseconds when missing
-      //   2015-08-16T08:20:05+0000 => 2015-08-16T08:20:05.000+0000
-      str = str.replaceAll("(:\\d{1,2})([+-]\\d{4})\\z", "$1.000$2");
+      //   2015-08-16T08:20:05+00:00 => 2015-08-16T08:20:05.000+00:00
+      str = str.replaceAll("(:\\d{1,2})([+-]\\d{2}:\\d{2})\\z", "$1.000$2");
     }
 
     try {
-      return datetimeFormatter.parse(str);
+      return datetimeFormat.parse(str);
     } catch (ParseException e) {
       throw new RuntimeException(e);
     }
@@ -289,14 +299,14 @@ public class ApiClient {
    * Format the given Date object into string.
    */
   public String formatDate(Date date) {
-    return dateFormatter.format(date);
+    return dateFormat.format(date);
   }
 
   /**
    * Format the given Date object into string.
    */
   public String formatDatetime(Date date) {
-    return datetimeFormatter.format(date);
+    return datetimeFormat.format(date);
   }
 
   /**
diff --git a/samples/client/petstore/java/okhttp-gson/src/test/java/io/swagger/client/ApiClientTest.java b/samples/client/petstore/java/okhttp-gson/src/test/java/io/swagger/client/ApiClientTest.java
index 802c0cae3b9..aaf4f33c49e 100644
--- a/samples/client/petstore/java/okhttp-gson/src/test/java/io/swagger/client/ApiClientTest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/test/java/io/swagger/client/ApiClientTest.java
@@ -2,7 +2,10 @@ package io.swagger.client;
 
 import io.swagger.client.auth.*;
 
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
 import java.util.*;
+import java.util.TimeZone;
 
 import org.junit.*;
 import static org.junit.Assert.*;
@@ -16,6 +19,64 @@ public class ApiClientTest {
         apiClient = new ApiClient();
     }
 
+    @Test
+    public void testParseAndFormatDatetime() {
+        // default datetime format with UTC time zone
+        apiClient.getDatetimeFormat().setTimeZone(TimeZone.getTimeZone("UTC"));
+        String dateStr = "2015-11-07T03:49:09.356Z";
+        assertTrue(apiClient.isLenientDatetimeFormat());
+        assertEquals(dateStr, apiClient.formatDatetime(apiClient.parseDatetime("2015-11-07T03:49:09.356+00:00")));
+        assertEquals(dateStr, apiClient.formatDatetime(apiClient.parseDatetime("2015-11-07T05:49:09.356+02:00")));
+        assertEquals(dateStr, apiClient.formatDatetime(apiClient.parseDatetime("2015-11-07T02:49:09.356-01:00")));
+        // support various cases
+        assertEquals(dateStr, apiClient.formatDatetime(apiClient.parseDatetime("2015-11-07T03:49:09.356Z")));
+        assertEquals(dateStr, apiClient.formatDatetime(apiClient.parseDatetime("2015-11-07T03:49:09.356+00")));
+        assertEquals(dateStr, apiClient.formatDatetime(apiClient.parseDatetime("2015-11-07T02:49:09.356-0100")));
+        dateStr = "2015-11-07T03:49:09.000Z";
+        assertEquals(dateStr, apiClient.formatDatetime(apiClient.parseDatetime("2015-11-07T05:49:09+02")));
+
+        // custom datetime format: without milli-seconds, custom time zone
+        DateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssXXX");
+        format.setTimeZone(TimeZone.getTimeZone("GMT+10"));
+        apiClient.setDatetimeFormat(format);
+        // disable support of various datetime format
+        apiClient.setLenientDatetimeFormat(false);
+        dateStr = "2015-11-07T13:49:09+10:00";
+        assertEquals(dateStr, apiClient.formatDatetime(apiClient.parseDatetime("2015-11-07T03:49:09+00:00")));
+        assertEquals(dateStr, apiClient.formatDatetime(apiClient.parseDatetime("2015-11-07T03:49:09Z")));
+        assertEquals(dateStr, apiClient.formatDatetime(apiClient.parseDatetime("2015-11-07T00:49:09-03:00")));
+
+        try {
+            // invalid time zone format
+            apiClient.parseDatetime("2015-11-07T03:49:09+00");
+            fail("parseDatetime should fail");
+        } catch (RuntimeException e) {
+            // OK
+        }
+        try {
+            // unexpected miliseconds
+            apiClient.parseDatetime("2015-11-07T03:49:09.000Z");
+            fail("parseDatetime should fail");
+        } catch (RuntimeException e) {
+            // OK
+        }
+    }
+
+    @Test
+    public void testParseAndFormatDate() {
+        // default date format
+        String dateStr = "2015-11-07";
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDatetime("2015-11-07T03:49:09.356+00:00")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11-07")));
+
+        // custom date format: without day
+        DateFormat format = new SimpleDateFormat("yyyy-MM");
+        apiClient.setDateFormat(format);
+        dateStr = "2015-11";
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDatetime("2015-11-07T03:49:09Z")));
+        assertEquals(dateStr, apiClient.formatDate(apiClient.parseDate("2015-11")));
+    }
+
     @Test
     public void testSelectHeaderAccept() {
         String[] accepts = {"APPLICATION/JSON", "APPLICATION/XML"};
diff --git a/samples/client/petstore/java/okhttp-gson/src/test/java/io/swagger/client/JSONTest.java b/samples/client/petstore/java/okhttp-gson/src/test/java/io/swagger/client/JSONTest.java
new file mode 100644
index 00000000000..fdc2e4c7d4a
--- /dev/null
+++ b/samples/client/petstore/java/okhttp-gson/src/test/java/io/swagger/client/JSONTest.java
@@ -0,0 +1,55 @@
+package io.swagger.client;
+
+import com.google.gson.reflect.TypeToken;
+
+import io.swagger.client.model.Order;
+
+import java.lang.Exception;
+import java.lang.reflect.Type;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.*;
+
+import org.junit.*;
+import static org.junit.Assert.*;
+
+public class JSONTest {
+    ApiClient apiClient = null;
+    JSON json = null;
+    Order order = null;
+
+    @Before
+    public void setup() {
+        apiClient = new ApiClient();
+        json = new JSON(apiClient);
+        order = new Order();
+    }
+
+    @Test
+    public void testDefaultDate() throws Exception {
+        final DateFormat datetimeFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
+        datetimeFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
+        final String dateStr = "2015-11-07T14:11:05.267Z";
+        order.setShipDate(datetimeFormat.parse(dateStr));
+
+        String str = json.serialize(order);
+        Type type = new TypeToken<Order>() { }.getType();
+        Order o = json.deserialize(str, type);
+        assertEquals(dateStr, datetimeFormat.format(o.getShipDate()));
+    }
+
+    @Test
+    public void testCustomDate() throws Exception {
+        final DateFormat datetimeFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssXXX");
+        datetimeFormat.setTimeZone(TimeZone.getTimeZone("GMT-2"));
+        final String dateStr = "2015-11-07T14:11:05-02:00";
+        order.setShipDate(datetimeFormat.parse(dateStr));
+
+        apiClient.setDatetimeFormat(datetimeFormat);
+        apiClient.setLenientDatetimeFormat(false);
+        String str = json.serialize(order);
+        Type type = new TypeToken<Order>() { }.getType();
+        Order o = json.deserialize(str, type);
+        assertEquals(dateStr, datetimeFormat.format(o.getShipDate()));
+    }
+}
\ No newline at end of file
diff --git a/samples/client/petstore/java/okhttp-gson/src/test/java/io/swagger/petstore/test/StoreApiTest.java b/samples/client/petstore/java/okhttp-gson/src/test/java/io/swagger/petstore/test/StoreApiTest.java
index a1fd7e345a8..589dae1a3ca 100644
--- a/samples/client/petstore/java/okhttp-gson/src/test/java/io/swagger/petstore/test/StoreApiTest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/test/java/io/swagger/petstore/test/StoreApiTest.java
@@ -8,6 +8,7 @@ import io.swagger.client.auth.*;
 import io.swagger.client.model.*;
 
 import java.util.Map;
+import java.text.SimpleDateFormat;
 
 import org.junit.*;
 import static org.junit.Assert.*;
@@ -21,6 +22,12 @@ public class StoreApiTest {
         // setup authentication
         ApiKeyAuth apiKeyAuth = (ApiKeyAuth) api.getApiClient().getAuthentication("api_key");
         apiKeyAuth.setApiKey("special-key");
+        // set custom date format that is used by the petstore server
+        // Note: it would still work without this setting as okhttp-gson Java client supports
+        // various date formats by default (with lenientDatetimeFormat enabled), including
+        // the one used by petstore server
+        api.getApiClient().setDatetimeFormat(new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ"));
+        api.getApiClient().setLenientDatetimeFormat(false);
     }
 
     @Test