diff --git a/src/AEMO.MDFF.Tests/NEM12/BasicTest.cs b/src/AEMO.MDFF.Tests/NEM12/BasicTest.cs
index 936a106..7f2abeb 100644
--- a/src/AEMO.MDFF.Tests/NEM12/BasicTest.cs
+++ b/src/AEMO.MDFF.Tests/NEM12/BasicTest.cs
@@ -27,8 +27,9 @@ public async Task Test1()
                 case NMIDataDetailsRecord { NextScheduledReadDate: var nsrd }:
                     _testOutputHelper.WriteLine(nsrd.ToLongDateString());
                     break;
-                case IntervalDataRecord { IntervalValues: var ivs }:
-                    _testOutputHelper.WriteLine(ivs.ToString());
+                case IntervalDataRecord intervalDataRecord:
+                    _testOutputHelper.WriteLine(intervalDataRecord.IntervalValues.ToString());
+                    _testOutputHelper.WriteLine(intervalDataRecord.UpdateDateTime.ToLongTimeString());
                     break;
             }
         }
diff --git a/src/AEMO.MDFF/NEM12/IntervalDataRecord.cs b/src/AEMO.MDFF/NEM12/IntervalDataRecord.cs
index f26b25e..7d86dc7 100644
--- a/src/AEMO.MDFF/NEM12/IntervalDataRecord.cs
+++ b/src/AEMO.MDFF/NEM12/IntervalDataRecord.cs
@@ -10,6 +10,6 @@ public sealed class IntervalDataRecord : IMdffRecord
     public string QualityMethod { get; set; }
     public string ReasonCode { get; set; }
     public string ReasonDescription { get; set; }
-    public string UpdateDateTime { get; set; }
+    public DateTime UpdateDateTime { get; set; }
     public DateTime MSATSLoadDateTime { get; set; }
 }
\ No newline at end of file
diff --git a/src/AEMO.MDFF/NEM12/Nem12Reader.cs b/src/AEMO.MDFF/NEM12/Nem12Reader.cs
index fa48571..d95ae0f 100644
--- a/src/AEMO.MDFF/NEM12/Nem12Reader.cs
+++ b/src/AEMO.MDFF/NEM12/Nem12Reader.cs
@@ -105,10 +105,10 @@ private NMIDataDetailsRecord ParseNMIDataDetailsRecord(CsvDataReader csv)
     
     private IntervalDataRecord ParseIntervalDataRecord(CsvDataReader csv, string currentNMI)
     {
-        var dateString = csv.GetString(1);
-        var date = DateOnly.ParseExact(dateString, "yyyyMMdd", CultureInfo.InvariantCulture);
+        var intervalDate = DateOnly.ParseExact(csv.GetString(1), "yyyyMMdd", CultureInfo.InvariantCulture);
         int intervalLength = _nmiIntervalLengths[currentNMI];
         int expectedIntervals = 1440 / intervalLength; // 1440 minutes in a day
+        var updateDateTime = DateTime.ParseExact(csv.GetString(2 + expectedIntervals + 3), "yyyyMMddHHmmss", CultureInfo.InvariantCulture);
 
         var intervalValues = new List<decimal>();
         for (int i = 2; i < expectedIntervals + 2; i++)
@@ -118,8 +118,9 @@ private IntervalDataRecord ParseIntervalDataRecord(CsvDataReader csv, string cur
 
         return new IntervalDataRecord
         {
-            IntervalDate = date,
-            IntervalValues = intervalValues
+            IntervalDate = intervalDate,
+            IntervalValues = intervalValues,
+            UpdateDateTime = updateDateTime,
         };
     }
 }
\ No newline at end of file