diff --git a/python/cortex.py b/python/cortex.py
index 98c879f..447216a 100644
--- a/python/cortex.py
+++ b/python/cortex.py
@@ -56,6 +56,7 @@
 REFRESH_HEADSET_LIST_ID             =   25
 QUERY_RECORDS_ID                    =   26
 REQUEST_DOWNLOAD_RECORDS_ID         =   27
+SYNC_WITH_HEADSET_CLOCK_ID          =   28
 
 #define error_code
 ERR_PROFILE_ACCESS_DENIED = -32046
@@ -89,7 +90,7 @@ class Cortex(Dispatcher):
                 'warn_record_post_processing_done', 'query_records_done', 'request_download_records_done',
                 'inject_marker_done', 'update_marker_done', 'export_record_done', 'new_data_labels', 
                 'new_com_data', 'new_fe_data', 'new_eeg_data', 'new_mot_data', 'new_dev_data', 
-                'new_met_data', 'new_pow_data', 'new_sys_data']
+                'new_met_data', 'new_pow_data', 'new_sys_data', 'sync_with_headset_clock_done']
     def __init__(self, client_id, client_secret, debug_mode=False, **kwargs):
         """
         Initialize a Cortex instance with authentication and configuration options.
@@ -220,6 +221,7 @@ def _get_result_handler(self, req_id):
             EXPORT_RECORD_ID: self._handle_export_record,
             INJECT_MARKER_REQUEST_ID: self._handle_inject_marker_request,
             UPDATE_MARKER_REQUEST_ID: self._handle_update_marker_request,
+            SYNC_WITH_HEADSET_CLOCK_ID: self._handle_sync_with_headset_clock
         }
         return handlers.get(req_id)
 
@@ -420,6 +422,9 @@ def _handle_inject_marker_request(self, result_dic):
     def _handle_update_marker_request(self, result_dic):
         self.emit('update_marker_done', data=result_dic['marker'])
 
+    def _handle_sync_with_headset_clock(self, result_dic):
+        self.emit('sync_with_headset_clock_done', data=result_dic)
+
     def handle_error(self, recv_dic):
         req_id = recv_dic['id']
         print('handle_error: request Id ' + str(req_id))
@@ -1091,6 +1096,29 @@ def refresh_headset_list(self):
 
         self.ws.send(json.dumps(refresh_request, indent=4))
 
+    def sync_with_headset_clock(self, headset_id=None):
+        print('sync with headset clock --------------------------------')
+
+        # Use instance headset_id if not provided
+        if headset_id is None:
+            headset_id = self.headset_id
+
+        sync_request = {
+            "jsonrpc": "2.0",
+            "id": SYNC_WITH_HEADSET_CLOCK_ID,  # Using next available ID
+            "method": "syncWithHeadsetClock",
+            "params": {
+                "headset": headset_id,
+                "systemTime": time.time(),
+                "monotonicTime": time.monotonic()
+            }
+        }
+
+        if self.debug:
+            print('sync with headset clock request \n', json.dumps(sync_request, indent=4))
+
+        self.ws.send(json.dumps(sync_request))
+
 # -------------------------------------------------------------------
 # -------------------------------------------------------------------
 # -------------------------------------------------------------------
diff --git a/python/marker.py b/python/marker.py
index 1c75355..c1f66de 100644
--- a/python/marker.py
+++ b/python/marker.py
@@ -12,6 +12,8 @@ def __init__(self, app_client_id, app_client_secret, **kwargs):
         self.c.bind(export_record_done=self.on_export_record_done)
         self.c.bind(inform_error=self.on_inform_error)
         self.c.bind(warn_record_post_processing_done=self.on_warn_record_post_processing_done)
+        self.c.bind(sync_with_headset_clock_done=self.on_sync_with_headset_clock_done)
+        self.headset_clock_adjustment = 0
 
     def start(self, number_markers=10, headset_id=''):
         """
@@ -73,7 +75,7 @@ def export_record(self, folder, stream_types, export_format, record_ids,
     def add_markers(self):
         print('add_markers: ' + str(self.number_markers) + ' markers will be injected each second automatically.')
         for m in range(self.number_markers):
-            marker_time = time.time()*1000
+            marker_time = (time.monotonic() + self.headset_clock_adjustment) * 1000
             print('add marker at : ', marker_time)
             
             # marker_value = "test marker value"
@@ -112,6 +114,14 @@ def update_marker(self, marker_id, time, **kwargs):
     def on_create_session_done(self, *args, **kwargs):
         print('on_create_session_done')
 
+        # sync with headset clock before creating record
+        self.c.sync_with_headset_clock()
+
+    def on_sync_with_headset_clock_done(self, *args, **kwargs):
+        print('on_sync_with_headset_clock_done')
+        data = kwargs.get('data') or {}
+        self.headset_clock_adjustment = data.get('adjustment', 0)
+        print(f'Headset clock adjustment: {self.headset_clock_adjustment} s')
         # create a record
         self.create_record(self.record_title, description=self.record_description)