Fix for XSLT extension methods format-date & format-time

src/libraries/System.Private.Xml/src/System.Private.Xml.csproj

@@ -42,6 +42,14 @@
       <AutoGen>True</AutoGen>
       <DependentUpon>TextUtf8RawTextWriter.tt</DependentUpon>
     </Compile>
+    <Compile Include="System\Xml\Schema\DateAndTime\Converters\DateAndTimeConverter.cs" />
+    <Compile Include="System\Xml\Schema\DateAndTime\Helpers\DateAndTimeInfo.cs" />
+    <Compile Include="System\Xml\Schema\DateAndTime\Helpers\DateInfo.cs" />
+    <Compile Include="System\Xml\Schema\DateAndTime\Helpers\TimeInfo.cs" />
+    <Compile Include="System\Xml\Schema\DateAndTime\Specifications\DateTimeTypeCode.cs" />
+    <Compile Include="System\Xml\Schema\DateAndTime\Specifications\XsdDateTimeKind.cs" />
+    <Compile Include="System\Xml\Schema\DateAndTime\XsdDate.cs" />
+    <Compile Include="System\Xml\Schema\DateAndTime\XsdTime.cs" />
     <None Include="System\Xml\Core\HtmlEncodedRawTextWriter.tt">
       <Generator>TextTemplatingFileGenerator</Generator>
       <LastGenOutput>HtmlEncodedRawTextWriter.cs</LastGenOutput>

src/libraries/System.Private.Xml/src/System/Xml/Schema/DateAndTime/Helpers/DateAndTimeInfo.cs

@@ -0,0 +1,44 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Xml.Schema.DateAndTime.Specifications;
+
+namespace System.Xml.Schema.DateAndTime.Helpers
+{
+    internal struct DateAndTimeInfo
+    {
+        public DateInfo Date { get; }
+        public XsdDateTimeKind Kind { get; }
+        public TimeInfo Time { get; }
+        public DateTimeTypeCode TypeCode { get; }
+        public int ZoneHour { get; }
+        public int ZoneMinute { get; }
+
+        public DateAndTimeInfo(
+            DateInfo date,
+            XsdDateTimeKind kind,
+            TimeInfo time,
+            DateTimeTypeCode typeCode,
+            int zoneHour,
+            int zoneMinute)
+        {
+            Date = date;
+            Kind = kind;
+            Time = time;
+            TypeCode = typeCode;
+            ZoneHour = zoneHour;
+            ZoneMinute = zoneMinute;
+        }
+
+        public DateAndTimeInfo()
+            : this(
+                  default,
+                  XsdDateTimeKind.Unspecified,
+                  default,
+                  default,
+                  0,
+                  0)
+        {
+        }
+    }
+}

src/libraries/System.Private.Xml/src/System/Xml/Schema/DateAndTime/Helpers/DateInfo.cs

@@ -0,0 +1,25 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System.Xml.Schema.DateAndTime.Helpers
+{
+    internal struct DateInfo
+    {
+        public static readonly DateInfo DefaultValue = new DateInfo(FirstDay, FirstMonth, LeapYear);
+
+        public const int FirstDay = 1;
+        public const int FirstMonth = 1;
+        public const int LeapYear = 1904;
+
+        public int Day { get; }
+        public int Month { get; }
+        public int Year { get; }
+
+        public DateInfo(int day, int month, int year)
+        {
+            Day = day;
+            Month = month;
+            Year = year;
+        }
+    }
+}

src/libraries/System.Private.Xml/src/System/Xml/Schema/DateAndTime/Helpers/TimeInfo.cs

@@ -0,0 +1,37 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System.Xml.Schema.DateAndTime.Helpers
+{
+    internal struct TimeInfo
+    {
+        public int Fraction { get; }
+        public int Hour { get; }
+        public int Microsecond
+        {
+            get
+            {
+                return Convert.ToInt32((Fraction % TimeSpan.TicksPerMillisecond) / TimeSpan.TicksPerMicrosecond);
+            }
+        }
+
+        public int Millisecond
+        {
+            get
+            {
+                return Convert.ToInt32(Fraction / TimeSpan.TicksPerMillisecond);
+            }
+        }
+
+        public int Minute { get; }
+        public int Second { get; }
+
+        public TimeInfo(int fraction, int hour, int minute, int second)
+        {
+            Fraction = fraction;
+            Hour = hour;
+            Minute = minute;
+            Second = second;
+        }
+    }
+}

src/libraries/System.Private.Xml/src/System/Xml/Schema/DateAndTime/Specifications/DateTimeTypeCode.cs

@@ -0,0 +1,21 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System.Xml.Schema.DateAndTime.Specifications
+{
+    /// <summary>
+    /// Subset of represented XML Schema types.
+    /// </summary>
+    internal enum DateTimeTypeCode
+    {
+        DateTime,
+        Time,
+        Date,
+        GYearMonth,
+        GYear,
+        GMonthDay,
+        GDay,
+        GMonth,
+        XdrDateTime,
+    }
+}

src/libraries/System.Private.Xml/src/System/Xml/Schema/DateAndTime/Specifications/XsdDateTimeKind.cs

@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System.Xml.Schema.DateAndTime.Specifications
+{
+    /// <summary>
+    /// Internal representation of <see cref="System.DateTimeKind"/>.
+    /// </summary>
+    internal enum XsdDateTimeKind
+    {
+        Unspecified,
+        Zulu,
+        LocalWestOfZulu,    // GMT-1..14, N..Y
+        LocalEastOfZulu     // GMT+1..14, A..M
+    }
+}

src/libraries/System.Private.Xml/src/System/Xml/Schema/DateAndTime/XsdDate.cs

@@ -0,0 +1,37 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Xml.Schema.DateAndTime.Converters;
+using System.Xml.Schema.DateAndTime.Helpers;
+
+namespace System.Xml.Schema.DateAndTime
+{
+    internal struct XsdDate : IFormattable
+    {
+        private DateOnly Date { get; set; }
+
+        private XsdDate(DateInfo parsedValue)
+            : this()
+        {
+            Date = new DateOnly(parsedValue.Year, parsedValue.Month, parsedValue.Day);
+        }
+
+        /// <inheritdoc/>
+        public string ToString(string? format, IFormatProvider? formatProvider)
+        {
+            return Date.ToString(format, formatProvider);
+        }
+
+        internal static bool TryParse(string text, out XsdDate result)
+        {
+            if (!DateAndTimeConverter.TryParse(text, out DateInfo parsedValue))
+            {
+                result = default;
+                return false;
+            }
+
+            result = new XsdDate(parsedValue);
+            return true;
+        }
+    }
+}

src/libraries/System.Private.Xml/src/System/Xml/Schema/DateAndTime/XsdTime.cs

@@ -0,0 +1,42 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Xml.Schema.DateAndTime.Converters;
+using System.Xml.Schema.DateAndTime.Helpers;
+
+namespace System.Xml.Schema.DateAndTime
+{
+    internal struct XsdTime : IFormattable
+    {
+        private TimeOnly Time { get; set; }
+
+        private XsdTime(TimeInfo parsedValue)
+            : this()
+        {
+            Time = new TimeOnly(
+                parsedValue.Hour,
+                parsedValue.Minute,
+                parsedValue.Second,
+                parsedValue.Millisecond,
+                parsedValue.Microsecond);
+        }
+
+        /// <inheritdoc/>
+        public string ToString(string? format, IFormatProvider? formatProvider)
+        {
+            return Time.ToString(format, formatProvider);
+        }
+
+        internal static bool TryParse(string text, out XsdTime result)
+        {
+            if (!DateAndTimeConverter.TryParse(text, out TimeInfo parsedValue))
+            {
+                result = default;
+                return false;
+            }
+
+            result = new XsdTime(parsedValue);
+            return true;
+        }
+    }
+}