diff --git a/ISOv4Plugin/Mappers/TimeLogMapper.cs b/ISOv4Plugin/Mappers/TimeLogMapper.cs
index 4922ace..13a39bb 100644
--- a/ISOv4Plugin/Mappers/TimeLogMapper.cs
+++ b/ISOv4Plugin/Mappers/TimeLogMapper.cs
@@ -33,6 +33,8 @@ internal TimeLogMapper(TaskDataMapper taskDataMapper) : base(taskDataMapper, "TL
         {
         }
 
+        private static readonly DateTime _firstDayOf1980 = new DateTime(1980, 1, 1, 0, 0, 0, DateTimeKind.Local);
+
         #region Export
         private Dictionary<int, int> _dataLogValueOrdersByWorkingDataID;
         public IEnumerable<ISOTimeLog> ExportTimeLogs(IEnumerable<OperationData> operationDatas, string dataPath)
@@ -150,7 +152,6 @@ private class BinaryWriter
         {   // ATTENTION: CoordinateMultiplier and ZMultiplier also exist in Import\SpatialRecordMapper.cs!
             private const double CoordinateMultiplier = 0.0000001;
             private const double ZMultiplier = 0.001;   // In ISO the PositionUp value is specified in mm.
-            private readonly DateTime _januaryFirst1980 = new DateTime(1980, 1, 1);
 
             private readonly IEnumeratedValueMapper _enumeratedValueMapper;
             private readonly INumericValueMapper _numericValueMapper;
@@ -193,7 +194,7 @@ private void WriteSpatialRecord(SpatialRecord spatialRecord, List<WorkingData> m
                 var millisecondsSinceMidnight = (UInt32)new TimeSpan(0, spatialRecord.Timestamp.Hour, spatialRecord.Timestamp.Minute, spatialRecord.Timestamp.Second, spatialRecord.Timestamp.Millisecond).TotalMilliseconds;
                 memoryStream.Write(BitConverter.GetBytes(millisecondsSinceMidnight), 0, 4);
 
-                var daysSinceJanOne1980 = (UInt16)(spatialRecord.Timestamp - (_januaryFirst1980)).TotalDays;
+                var daysSinceJanOne1980 = (UInt16)(spatialRecord.Timestamp - _firstDayOf1980).TotalDays;
                 memoryStream.Write(BitConverter.GetBytes(daysSinceJanOne1980), 0, 2);
 
                 //Position
@@ -753,8 +754,6 @@ internal static Dictionary<byte, int> ReadImplementGeometryValues(IEnumerable<by
 
         protected class BinaryReader
         {
-            private static readonly DateTime _firstDayOf1980 = new DateTime(1980, 01, 01);
-
             public static Dictionary<byte, int> ReadImplementGeometryValues(string filePath, ISOTime templateTime, IEnumerable<byte> desiredDLVIndices, int version, IList<IError> errors)
             {
                 Dictionary<byte, int> output = new Dictionary<byte, int>();