diff --git a/S7.Net/Helper/DateTimeExtensions.cs b/S7.Net/Helper/DateTimeExtensions.cs
index 7e128c1..62432ee 100644
--- a/S7.Net/Helper/DateTimeExtensions.cs
+++ b/S7.Net/Helper/DateTimeExtensions.cs
@@ -10,11 +10,11 @@ namespace S7.Net.Helper
         {
             if (dateTime < Date.IecMinDate)
             {
-                throw new ArgumentException($"DateTime must be at least {Date.IecMinDate:d}");
+                throw new ArgumentOutOfRangeException($"DateTime must be at least {Date.IecMinDate:d}");
             }
             if (dateTime > Date.IecMaxDate)
             {
-                throw new ArgumentException($"DateTime must be lower than {Date.IecMaxDate:d}");
+                throw new ArgumentOutOfRangeException($"DateTime must be lower than {Date.IecMaxDate:d}");
             }
 
             return (ushort)(dateTime - Date.IecMinDate).TotalDays;