diff --git a/AsbCloudInfrastructure/Services/Subsystems/Interpolation.cs b/AsbCloudInfrastructure/Services/Subsystems/Interpolation.cs
index 56601561..cf87da98 100644
--- a/AsbCloudInfrastructure/Services/Subsystems/Interpolation.cs
+++ b/AsbCloudInfrastructure/Services/Subsystems/Interpolation.cs
@@ -8,7 +8,7 @@ namespace AsbCloudInfrastructure.Services.Subsystems.Utils
     internal class Interpolation
     {
         private IEnumerator<(DateTimeOffset dateMin, float? depthMin, DateTimeOffset dateMax, float? depthMax)> enumerator;
-        (DateTimeOffset dateMin, float? depthMin, DateTimeOffset dateMax, float? depthMax) lastValue = default;
+        (DateTimeOffset x, float? y) lastValue = default;
 
         public Interpolation(IOrderedEnumerable<(DateTimeOffset dateMin, float? depthMin, DateTimeOffset dateMax, float? depthMax)> collection)
         {
@@ -17,18 +17,19 @@ namespace AsbCloudInfrastructure.Services.Subsystems.Utils
         }
 
         public float GetDepth(DateTimeOffset date)
-        {
-            if (lastValue.depthMin is not null &&
-                lastValue.depthMax is not null)
+        {            
             {
-                while (date > enumerator.Current.dateMax)
+                while (date >= enumerator.Current.dateMax)
                 {
                     if (isLess(date))
-                        CalcValue(enumerator.Current, date.Second);
+                    {
+                        lastValue.x = date;
+                        lastValue.y = CalcValue(enumerator.Current, date.Second);
+                    }
                     enumerator.MoveNext();
                 }
             }
-            return (float)lastValue.depthMin;
+            return (float)lastValue.y;
         }
         
         private bool isLess(DateTimeOffset date)
diff --git a/AsbCloudInfrastructure/Services/Subsystems/SubsystemOperationTimeBackgroundService.cs b/AsbCloudInfrastructure/Services/Subsystems/SubsystemOperationTimeBackgroundService.cs
index fc63e795..b2cf39fc 100644
--- a/AsbCloudInfrastructure/Services/Subsystems/SubsystemOperationTimeBackgroundService.cs
+++ b/AsbCloudInfrastructure/Services/Subsystems/SubsystemOperationTimeBackgroundService.cs
@@ -265,7 +265,7 @@ namespace AsbCloudInfrastructure.Services.Subsystems
                 "   max(well_depth) as max_well_depth " +
                 "from " +
                 "   t_telemetry_data_saub " +
-                "where id_telemetry = @idTelemetry and \"date\" > @begin " +
+                "where id_telemetry = @idTelemetry and \"date\" >= @begin " +
                 "group by ceil(well_depth * 10) " +
                 "order by min_date; ";