diff --git a/lib/src/data_manager/session_id_creator.dart b/lib/src/data_manager/session_id_creator.dart
index eaa7c75..ff33b7e 100644
--- a/lib/src/data_manager/session_id_creator.dart
+++ b/lib/src/data_manager/session_id_creator.dart
@@ -1,6 +1,8 @@
-String createSessionID(
-    {required String participantID, required String startTime}) {
-  final String sessionID = participantID + startTime;
+/// Create a unique [String] identifier by concatenating the [participantID]
+/// with the current time.
+String createSessionID({required String participantID}) {
+  final DateTime startTime = DateTime.now();
+  final String sessionID = "${participantID}_${startTime.toString()}";
 
   return sessionID;
 }
diff --git a/lib/src/services/run_session.dart b/lib/src/services/run_session.dart
index fa5409c..75cbd3d 100644
--- a/lib/src/services/run_session.dart
+++ b/lib/src/services/run_session.dart
@@ -21,7 +21,6 @@ void runSession(
   /// session id for both practice and experimental data.
   final String sessionID = createSessionID(
     participantID: participantID,
-    startTime: TimeOfDay.now().toString(),
   );
 
   DigitSpanTaskData data = await taskRunner(