diff --git a/src/MTConnect.NET-Common/Agents/MTConnectAgent.cs b/src/MTConnect.NET-Common/Agents/MTConnectAgent.cs
index 35e8d5c8..05e6c507 100644
--- a/src/MTConnect.NET-Common/Agents/MTConnectAgent.cs
+++ b/src/MTConnect.NET-Common/Agents/MTConnectAgent.cs
@@ -758,7 +758,7 @@ private static bool FilterPeriod(IDataItem dataItem, long newTimestamp, long exi
                                 var period = TimeSpan.FromSeconds(filter.Value);
 
                                 // Get Duration between newTimestamp and existingTimestamp
-                                var duration = TimeSpan.FromMilliseconds(newTimestamp - existingTimestamp);
+                                var duration = TimeSpan.FromTicks(newTimestamp - existingTimestamp);
 
                                 return duration > period;
                             }