-Added support for 24 hour ISO dates

Src/Newtonsoft.Json.Tests/Utilities/DateTimeUtilsTests.cs

@@ -70,6 +70,32 @@ namespace Newtonsoft.Json.Tests.Utilities
             Assert.AreEqual(value, parsedDt);
         }
 
+        [Test]
+        public void Parse24HourDateTime()
+        {
+            DateTime dt;
+            Assert.IsTrue(DateTimeUtils.TryParseDateTimeIso(CreateStringReference("2000-12-15T24:00:00Z"), DateTimeZoneHandling.RoundtripKind, out dt));
+            Assert.AreEqual(new DateTime(2000, 12, 16, 0, 0, 0, DateTimeKind.Utc), dt);
+
+            Assert.IsFalse(DateTimeUtils.TryParseDateTimeIso(CreateStringReference("2000-12-15T24:01:00Z"), DateTimeZoneHandling.RoundtripKind, out dt));
+            Assert.IsFalse(DateTimeUtils.TryParseDateTimeIso(CreateStringReference("2000-12-15T24:00:01Z"), DateTimeZoneHandling.RoundtripKind, out dt));
+            Assert.IsFalse(DateTimeUtils.TryParseDateTimeIso(CreateStringReference("2000-12-15T24:00:00.0000001Z"), DateTimeZoneHandling.RoundtripKind, out dt));
+        }
+
+#if !NET20
+        [Test]
+        public void Parse24HourDateTimeOffset()
+        {
+            DateTimeOffset dt;
+            Assert.IsTrue(DateTimeUtils.TryParseDateTimeOffsetIso(CreateStringReference("2000-12-15T24:00:00Z"), out dt));
+            Assert.AreEqual(new DateTimeOffset(2000, 12, 16, 0, 0, 0, TimeSpan.Zero), dt);
+
+            Assert.IsFalse(DateTimeUtils.TryParseDateTimeOffsetIso(CreateStringReference("2000-12-15T24:01:00Z"), out dt));
+            Assert.IsFalse(DateTimeUtils.TryParseDateTimeOffsetIso(CreateStringReference("2000-12-15T24:00:01Z"), out dt));
+            Assert.IsFalse(DateTimeUtils.TryParseDateTimeOffsetIso(CreateStringReference("2000-12-15T24:00:00.0000001Z"), out dt));
+        }
+#endif
+
         [Test]
         public void NewDateTimeParse()
         {

Src/Newtonsoft.Json/JsonSerializerSettings.cs

@@ -138,7 +138,7 @@ namespace Newtonsoft.Json
         }
 
         /// <summary>
-        /// Gets or sets a collection <see cref="JsonConverter"/> that will be used during serialization.
+        /// Gets or sets a <see cref="JsonConverter"/> collection that will be used during serialization.
         /// </summary>
         /// <value>The converters.</value>
         public IList<JsonConverter> Converters { get; set; }

Src/Newtonsoft.Json/Utilities/DateTimeParser.cs

@@ -123,13 +123,14 @@ namespace Newtonsoft.Json.Utilities
         private bool ParseTime(ref int start)
         {
             if (!(Parse2Digit(start, out Hour)
-                  && Hour < 24
+                  && Hour <= 24
                   && ParseChar(start + LzHH, ':')
                   && Parse2Digit(start + LzHH_, out Minute)
                   && Minute < 60
                   && ParseChar(start + LzHH_mm, ':')
                   && Parse2Digit(start + LzHH_mm_, out Second)
-                  && Second < 60))
+                  && Second < 60
+                  && (Hour != 24 || (Minute == 0 && Second == 0)))) // hour can be 24 if minute/second is zero)
             {
                 return false;
             }
@@ -162,6 +163,11 @@ namespace Newtonsoft.Json.Utilities
 
                     Fraction *= Power10[MaxFractionDigits - numberOfDigits];
                 }
+
+                if (Hour == 24 && Fraction != 0)
+                {
+                    return false;
+                }
             }
             return true;
         }

Src/Newtonsoft.Json/Utilities/DateTimeUtils.cs

@@ -206,8 +206,7 @@ namespace Newtonsoft.Json.Utilities
                 return false;
             }
 
-            DateTime d = new DateTime(dateTimeParser.Year, dateTimeParser.Month, dateTimeParser.Day, dateTimeParser.Hour, dateTimeParser.Minute, dateTimeParser.Second);
-            d = d.AddTicks(dateTimeParser.Fraction);
+            DateTime d = CreateDateTime(dateTimeParser);
 
             long ticks;
 
@@ -269,8 +268,7 @@ namespace Newtonsoft.Json.Utilities
                 return false;
             }
 
-            DateTime d = new DateTime(dateTimeParser.Year, dateTimeParser.Month, dateTimeParser.Day, dateTimeParser.Hour, dateTimeParser.Minute, dateTimeParser.Second);
-            d = d.AddTicks(dateTimeParser.Fraction);
+            DateTime d = CreateDateTime(dateTimeParser);
 
             TimeSpan offset;
 
@@ -302,6 +300,29 @@ namespace Newtonsoft.Json.Utilities
         }
 #endif
 
+        private static DateTime CreateDateTime(DateTimeParser dateTimeParser)
+        {
+            bool is24Hour;
+            if (dateTimeParser.Hour == 24)
+            {
+                is24Hour = true;
+                dateTimeParser.Hour = 0;
+            }
+            else
+            {
+                is24Hour = false;
+            }
+
+            DateTime d = new DateTime(dateTimeParser.Year, dateTimeParser.Month, dateTimeParser.Day, dateTimeParser.Hour, dateTimeParser.Minute, dateTimeParser.Second);
+            d = d.AddTicks(dateTimeParser.Fraction);
+
+            if (is24Hour)
+            {
+                d = d.AddDays(1);
+            }
+            return d;
+        }
+
         internal static bool TryParseDateTime(StringReference s, DateTimeZoneHandling dateTimeZoneHandling, string dateFormatString, CultureInfo culture, out DateTime dt)
         {
             if (s.Length > 0)