➕ Add DateTime properties to DecodedMetar and DecodedTaf

src/Metar.Decoder/ChunkDecoder/DatetimeChunkDecoder.cs

@@ -7,6 +7,7 @@ public sealed class DatetimeChunkDecoder : MetarChunkDecoder
     {
         public const string DayParameterName = "Day";
         public const string TimeParameterName = "Time";
+        public const string ObservationDateTimeParameterName = "ObservationDateTime";
 
         public override string GetRegex()
         {
@@ -39,6 +40,27 @@ public override Dictionary<string, object> Parse(string remainingMetar, bool wit
             result.Add(DayParameterName, day);
             result.Add(TimeParameterName, $"{hour:00}:{minute:00} UTC");
 
+            // Create DateTime from parsed components
+            var currentYear = DateTime.Now.Year;
+            var month = DateTime.Now.Month;
+
+            // Handle day/year rollover - if day > current day, assume previous month
+            if (day > DateTime.Now.Day)
+            {
+                if (month == 1)
+                {
+                    month = 12;
+                    currentYear--;
+                }
+                else
+                {
+                    month--;
+                }
+            }
+
+            var observationDateTime = new DateTime(currentYear, month, day, hour, minute, 0, DateTimeKind.Utc);
+            result.Add(ObservationDateTimeParameterName, observationDateTime);
+
             return GetResults(newRemainingMetar, result);
         }
 

src/Metar.Decoder/Entity/DecodedMetar.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Collections.ObjectModel;
 
 namespace Metar.Decoder.Entity
@@ -78,10 +79,15 @@ public ReadOnlyCollection<MetarChunkDecoderException> DecodingExceptions
         public int? Day { get; set; }
 
         /// <summary>
-        /// Time of the observation, as a string
+        /// Time of observation, as a string
         /// </summary>
         public string Time { get; set; } = string.Empty;
 
+        /// <summary>
+        /// Date and time of observation
+        /// </summary>
+        public DateTime? ObservationDateTime { get; set; }
+
         /// <summary>
         /// Report status (AUTO or NIL)
         /// </summary>

src/Taf.Decoder/ChunkDecoder/DatetimeChunkDecoder.cs

@@ -7,6 +7,7 @@ public sealed class DatetimeChunkDecoder : TafChunkDecoder
     {
         public const string DayParameterName = "Day";
         public const string TimeParameterName = "Time";
+        public const string OriginDateTimeParameterName = "OriginDateTime";
 
         public override string GetRegex()
         {
@@ -38,6 +39,27 @@ public override Dictionary<string, object> Parse(string remainingTaf, bool withC
             result.Add(DayParameterName, day);
             result.Add(TimeParameterName, $"{hour:00}:{minute:00} UTC");
 
+            // Create DateTime from parsed components
+            var currentYear = DateTime.Now.Year;
+            var month = DateTime.Now.Month;
+
+            // Handle day/year rollover - if day > current day, assume previous month
+            if (day > DateTime.Now.Day)
+            {
+                if (month == 1)
+                {
+                    month = 12;
+                    currentYear--;
+                }
+                else
+                {
+                    month--;
+                }
+            }
+
+            var originDateTime = new DateTime(currentYear, month, day, hour, minute, 0, DateTimeKind.Utc);
+            result.Add(OriginDateTimeParameterName, originDateTime);
+
             return GetResults(newRemainingTaf, result);
         }
 

src/Taf.Decoder/Entity/DecodedTaf.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Collections.ObjectModel;
 
 namespace Taf.Decoder.entity
@@ -69,6 +70,11 @@ public ReadOnlyCollection<TafChunkDecoderException> DecodingExceptions
         /// </summary>
         public string Time { get; set; } = string.Empty;
 
+        /// <summary>
+        /// Date and time of origin
+        /// </summary>
+        public DateTime? OriginDateTime { get; set; }
+
         /// <summary>
         /// Forecast period
         /// </summary>