diff --git a/AsbCloudInfrastructure/Services/TelemetryAnalyticsService.cs b/AsbCloudInfrastructure/Services/TelemetryAnalyticsService.cs
index b761a5a0..99462fa9 100644
--- a/AsbCloudInfrastructure/Services/TelemetryAnalyticsService.cs
+++ b/AsbCloudInfrastructure/Services/TelemetryAnalyticsService.cs
@@ -161,8 +161,12 @@ namespace AsbCloudInfrastructure.Services
             if (telemetryId is null)
                 return null;
 
-            var unixBegin = (begin - new DateTime(1970, 1, 1)).TotalSeconds;
-            var unixEnd = (end - new DateTime(1970, 1, 1)).TotalSeconds;
+            var unixBegin = begin == default 
+                            ? 0 
+                            : (begin - new DateTime(1970, 1, 1)).TotalSeconds;
+            var unixEnd = end == default 
+                            ? (DateTime.Now - new DateTime(1970, 1, 1)).TotalSeconds 
+                            : (end - new DateTime(1970, 1, 1)).TotalSeconds;
 
             return await (from a in db.TelemetryAnalysis
                           where a.IdTelemetry == telemetryId &&