diff --git a/src/main/java/biz/paluch/logging/gelf/GelfMessageAssembler.java b/src/main/java/biz/paluch/logging/gelf/GelfMessageAssembler.java
index 90b047cc9..599c24bb0 100644
--- a/src/main/java/biz/paluch/logging/gelf/GelfMessageAssembler.java
+++ b/src/main/java/biz/paluch/logging/gelf/GelfMessageAssembler.java
@@ -116,6 +116,11 @@ public void initialize(PropertyProvider propertyProvider) {
         if (messageSize != null) {
             maximumMessageSize = Integer.parseInt(messageSize);
         }
+
+        String timestampPattern = propertyProvider.getProperty(PropertyProvider.PROPERTY_TIMESTAMP_PATTERN);
+        if (timestampPattern != null && !"".equals(timestampPattern)) {
+            this.timestampPattern = timestampPattern;
+        }
     }
 
     /**
diff --git a/src/main/java/biz/paluch/logging/gelf/PropertyProvider.java b/src/main/java/biz/paluch/logging/gelf/PropertyProvider.java
index 10c109413..930024d8f 100644
--- a/src/main/java/biz/paluch/logging/gelf/PropertyProvider.java
+++ b/src/main/java/biz/paluch/logging/gelf/PropertyProvider.java
@@ -33,6 +33,7 @@ public interface PropertyProvider {
     String PROPERTY_ADDITIONAL_FIELD_TYPE = "additionalFieldType.";
     String PROPERTY_ADDITIONAL_FIELDS = "additionalFields";
     String PROPERTY_ADDITIONAL_FIELD_TYPES = "additionalFieldTypes";
+    String PROPERTY_TIMESTAMP_PATTERN = "timestampPattern";
 
     String PROPERTY_FILTER = "filter";
     String PROPERTY_LEVEL = "level";
diff --git a/src/test/java/biz/paluch/logging/gelf/jul/GelfLogHandlerUnitTests.java b/src/test/java/biz/paluch/logging/gelf/jul/GelfLogHandlerUnitTests.java
index 9da187927..1b40b1e49 100644
--- a/src/test/java/biz/paluch/logging/gelf/jul/GelfLogHandlerUnitTests.java
+++ b/src/test/java/biz/paluch/logging/gelf/jul/GelfLogHandlerUnitTests.java
@@ -15,7 +15,7 @@ public class GelfLogHandlerUnitTests {
     private static final String HOST = "host";
     private static final int GRAYLOG_PORT = 1;
     private static final int MAXIMUM_MESSAGE_SIZE = 1234;
-    private static final String TIMESTAMP_PATTERN = "yyyy-MM-dd HH:mm:ss,SSSS";
+    private static final String TIMESTAMP_PATTERN = "yyyy-MM-dd'T'HH:mm:ss.SSSZ";
 
     @Test
     public void testSameFieldsGelfLogHandler() {
@@ -27,6 +27,7 @@ public void testSameFieldsGelfLogHandler() {
         sut.setGraylogHost(HOST);
         sut.setGraylogPort(GRAYLOG_PORT);
         sut.setMaximumMessageSize(MAXIMUM_MESSAGE_SIZE);
+        sut.setTimestampPattern(TIMESTAMP_PATTERN);
 
         sut.flush();
 
diff --git a/src/test/resources/jul/test-logging.properties b/src/test/resources/jul/test-logging.properties
index f74fffa4f..2162115a1 100644
--- a/src/test/resources/jul/test-logging.properties
+++ b/src/test/resources/jul/test-logging.properties
@@ -8,7 +8,7 @@ biz.paluch.logging.gelf.jul.GelfLogHandler.facility=java-test
 biz.paluch.logging.gelf.jul.GelfLogHandler.version=1.1
 biz.paluch.logging.gelf.jul.GelfLogHandler.extractStackTrace=true
 biz.paluch.logging.gelf.jul.GelfLogHandler.filterStackTrace=true
-biz.paluch.logging.gelf.jul.GelfLogHandler.timestampPattern=yyyy-MM-dd HH:mm:ss,SSSS
+biz.paluch.logging.gelf.jul.GelfLogHandler.timestampPattern=yyyy-MM-dd'T'HH:mm:ss.SSSZ
 biz.paluch.logging.gelf.jul.GelfLogHandler.maximumMessageSize=8192
 biz.paluch.logging.gelf.jul.GelfLogHandler.additionalFields=fieldName1=fieldValue1,fieldName2=fieldValue2
 biz.paluch.logging.gelf.jul.GelfLogHandler.additionalField.0=fieldName3=fieldValue3