diff --git a/services/telit/generate_location.py b/services/telit/generate_location.py
index ee11568..cc9ec43 100644
--- a/services/telit/generate_location.py
+++ b/services/telit/generate_location.py
@@ -8,6 +8,16 @@
 import argparse
 import datetime
 import os
+import time
+
+def epoch_to_elasticsearch_date(epoch):
+    """
+    strict_date_optional_time in elastic search format is
+    yyyy-MM-dd'T'HH:mm:ss.SSSZ
+    @rtype: string
+    """
+    return datetime.datetime.fromtimestamp(epoch, tz=datetime.UTC).strftime(
+        "%Y-%m-%dT%H:%M:%S.%f")[:-3] + "Z"
 
 def open_file_for_write(filename):
     return gzip.open(filename, 'at')
@@ -41,7 +51,8 @@ def main():
                         type=str)
     args = parser.parse_args()
     time_part = datetime.datetime.now().strftime(args.time_format)
-    document = {"date": time_part,"TPV": {"lat": args.latitude,"lon": args.longitude,"alt": args.altitude},"hwa": args.hwa}
+    document = {"date": epoch_to_elasticsearch_date(
+                                time.time()),"TPV": {"lat": args.latitude,"lon": args.longitude,"alt": args.altitude},"hwa": args.hwa}
     # create special entry specifically for elastic search
     document["location"] = {"lat": document["TPV"]["lat"],
                             "lon": document["TPV"]["lon"],