Optimize DateTimeOffset

src/libraries/System.Private.CoreLib/src/System/DateTime.Unix.cs

@@ -24,7 +24,7 @@ public static DateTime UtcNow
         private static ulong ToFileTimeLeapSecondsAware(long ticks) => default;
 
         // IsValidTimeWithLeapSeconds is not expected to be called at all for now on non-Windows platforms
-        internal static bool IsValidTimeWithLeapSeconds(int year, int month, int day, int hour, int minute, DateTimeKind kind) => false;
+        internal static bool IsValidTimeWithLeapSeconds(DateTime value) => false;
 
 #pragma warning restore IDE0060
     }

src/libraries/System.Private.CoreLib/src/System/DateTime.Windows.cs

@@ -41,26 +41,28 @@ public static unsafe DateTime UtcNow
         }
 
         [MethodImpl(MethodImplOptions.NoInlining)]
-        internal static unsafe bool IsValidTimeWithLeapSeconds(int year, int month, int day, int hour, int minute, DateTimeKind kind)
+        private static unsafe bool IsValidTimeWithLeapSeconds(DateTime value)
         {
             Interop.Kernel32.SYSTEMTIME time;
+            value.GetDate(out int year, out int month, out int day);
             time.Year = (ushort)year;
             time.Month = (ushort)month;
             time.DayOfWeek = 0; // ignored by TzSpecificLocalTimeToSystemTime/SystemTimeToFileTime
             time.Day = (ushort)day;
+            value.GetTime(out int hour, out int minute, out _);
             time.Hour = (ushort)hour;
             time.Minute = (ushort)minute;
             time.Second = 60;
             time.Milliseconds = 0;
 
-            if (kind != DateTimeKind.Utc)
+            if (value.Kind != DateTimeKind.Utc)
             {
                 Interop.Kernel32.SYSTEMTIME st;
                 if (Interop.Kernel32.TzSpecificLocalTimeToSystemTime(IntPtr.Zero, &time, &st) != Interop.BOOL.FALSE)
                     return true;
             }
 
-            if (kind != DateTimeKind.Local)
+            if (value.Kind != DateTimeKind.Local)
             {
                 ulong ft;
                 if (Interop.Kernel32.SystemTimeToFileTime(&time, &ft) != Interop.BOOL.FALSE)
@@ -82,7 +84,7 @@ private static unsafe DateTime FromFileTimeLeapSecondsAware(ulong fileTime)
 
         private static unsafe ulong ToFileTimeLeapSecondsAware(long ticks)
         {
-            DateTime dt = new(ticks);
+            DateTime dt = new((ulong)ticks);
             Interop.Kernel32.SYSTEMTIME time;
 
             dt.GetDate(out int year, out int month, out int day);

src/libraries/System.Private.CoreLib/src/System/Enum.cs

@@ -938,7 +938,7 @@ private static bool TryParseByValueOrName<TUnderlying, TStorage>(
                     return TryParseByName(enumType, value, ignoreCase, throwOnFailure, out Unsafe.As<TUnderlying, TStorage>(ref result));
                 }
 
-                NumberFormatInfo numberFormat = CultureInfo.InvariantCulture.NumberFormat;
+                NumberFormatInfo numberFormat = NumberFormatInfo.InvariantInfo;
                 const NumberStyles NumberStyle = NumberStyles.AllowLeadingSign | NumberStyles.AllowTrailingWhite;
 
                 Number.ParsingStatus status = Number.TryParseBinaryIntegerStyle(value, NumberStyle, numberFormat, out result);

src/libraries/System.Private.CoreLib/src/System/Globalization/DateTimeFormatInfo.cs

@@ -310,12 +310,23 @@ public static DateTimeFormatInfo CurrentInfo
             }
         }
 
-        public static DateTimeFormatInfo GetInstance(IFormatProvider? provider) =>
-            provider == null ? CurrentInfo :
-            provider is CultureInfo cultureProvider && !cultureProvider._isInherited ? cultureProvider.DateTimeFormat :
-            provider is DateTimeFormatInfo info ? info :
-            provider.GetFormat(typeof(DateTimeFormatInfo)) is DateTimeFormatInfo info2 ? info2 :
-            CurrentInfo; // Couldn't get anything, just use currentInfo as fallback
+        public static DateTimeFormatInfo GetInstance(IFormatProvider? provider)
+        {
+            return provider == null ? CurrentInfo : GetProviderNonNull(provider);
+
+            static DateTimeFormatInfo GetProviderNonNull(IFormatProvider provider)
+            {
+                if (provider.GetType() == typeof(CultureInfo) && ((CultureInfo)provider)._dateTimeInfo is { } info)
+                {
+                    return info;
+                }
+
+                return
+                    provider as DateTimeFormatInfo ??
+                    provider.GetFormat(typeof(DateTimeFormatInfo)) as DateTimeFormatInfo ??
+                    CurrentInfo;
+            }
+        }
 
         public object? GetFormat(Type? formatType)
         {

src/libraries/System.Private.CoreLib/src/System/Globalization/GregorianCalendarHelper.cs

@@ -58,6 +58,8 @@ internal sealed class GregorianCalendarHelper
         private readonly int m_minYear;
         private readonly Calendar m_Cal;
         private readonly EraInfo[] m_EraInfo;
+        private readonly long _minSupportedTicks;
+        private readonly long _maxSupportedTicks;
 
         // Construct an instance of gregorian calendar.
         internal GregorianCalendarHelper(Calendar cal, EraInfo[] eraInfo)
@@ -66,6 +68,8 @@ internal GregorianCalendarHelper(Calendar cal, EraInfo[] eraInfo)
             m_EraInfo = eraInfo;
             m_maxYear = eraInfo[0].maxEraYear;
             m_minYear = eraInfo[0].minEraYear;
+            _minSupportedTicks = cal.MinSupportedDateTime.Ticks;
+            _maxSupportedTicks = cal.MaxSupportedDateTime.Ticks;
         }
 
         // EraInfo.yearOffset:  The offset to Gregorian year when the era starts. Gregorian Year = Era Year + yearOffset
@@ -168,7 +172,9 @@ internal bool IsValidYear(int year, int era)
 
         internal void CheckTicksRange(long ticks)
         {
-            if (ticks < m_Cal.MinSupportedDateTime.Ticks || ticks > m_Cal.MaxSupportedDateTime.Ticks)
+            if (ticks < _minSupportedTicks || ticks > _maxSupportedTicks) ThrowOutOfRange();
+
+            void ThrowOutOfRange()
             {
                 throw new ArgumentOutOfRangeException(
                             "time",

src/libraries/System.Private.CoreLib/src/System/Globalization/NumberFormatInfo.cs

@@ -218,9 +218,9 @@ public static NumberFormatInfo GetInstance(IFormatProvider? formatProvider)
             static NumberFormatInfo GetProviderNonNull(IFormatProvider provider)
             {
                 // Fast path for a regular CultureInfo
-                if (provider is CultureInfo cultureProvider && !cultureProvider._isInherited)
+                if (provider.GetType() == typeof(CultureInfo) && ((CultureInfo)provider)._numInfo is { } info)
                 {
-                    return cultureProvider._numInfo ?? cultureProvider.NumberFormat;
+                    return info;
                 }
 
                 return

src/libraries/System.Private.CoreLib/src/System/IO/File.cs

@@ -174,9 +174,12 @@ public static SafeFileHandle OpenHandle(string path, FileMode mode = FileMode.Op
         // File and Directory UTC APIs treat a DateTimeKind.Unspecified as UTC whereas
         // ToUniversalTime treats this as local.
         internal static DateTimeOffset GetUtcDateTimeOffset(DateTime dateTime)
-            => dateTime.Kind == DateTimeKind.Unspecified
-                ? DateTime.SpecifyKind(dateTime, DateTimeKind.Utc)
-                : dateTime.ToUniversalTime();
+        {
+            if (dateTime.Kind == DateTimeKind.Local)
+                dateTime = dateTime.ToUniversalTime();
+
+            return new DateTimeOffset(dateTime.Ticks, default);
+        }
 
         public static void SetCreationTime(string path, DateTime creationTime)
             => FileSystem.SetCreationTime(Path.GetFullPath(path), creationTime, asDirectory: false);

src/libraries/System.Private.CoreLib/src/System/IO/FileSystem.Windows.cs

@@ -466,30 +466,24 @@ private static void SetFileTime(
             bool asDirectory,
             long creationTime = 0,
             long lastAccessTime = 0,
-            long lastWriteTime = 0,
-            long changeTime = 0,
-            uint fileAttributes = 0)
+            long lastWriteTime = 0)
         {
             using SafeFileHandle handle = OpenHandleToWriteAttributes(fullPath, asDirectory);
-            SetFileTime(handle, fullPath, creationTime, lastAccessTime, lastWriteTime, changeTime, fileAttributes);
+            SetFileTime(handle, fullPath, creationTime, lastAccessTime, lastWriteTime);
         }
 
         private static unsafe void SetFileTime(
             SafeFileHandle fileHandle,
             string? fullPath = null,
             long creationTime = 0,
             long lastAccessTime = 0,
-            long lastWriteTime = 0,
-            long changeTime = 0,
-            uint fileAttributes = 0)
+            long lastWriteTime = 0)
         {
             var basicInfo = new Interop.Kernel32.FILE_BASIC_INFO
             {
                 CreationTime = creationTime,
                 LastAccessTime = lastAccessTime,
                 LastWriteTime = lastWriteTime,
-                ChangeTime = changeTime,
-                FileAttributes = fileAttributes
             };
 
             if (!Interop.Kernel32.SetFileInformationByHandle(fileHandle, Interop.Kernel32.FileBasicInfo, &basicInfo, (uint)sizeof(Interop.Kernel32.FILE_BASIC_INFO)))

src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.StringSerializer.cs

@@ -535,8 +535,7 @@ private TransitionTime GetNextTransitionTimeValue()
 
                 TransitionTime transition;
 
-                DateTime timeOfDay = GetNextDateTimeValue(TimeOfDayFormat);
-                timeOfDay = new DateTime(1, 1, 1, timeOfDay.Hour, timeOfDay.Minute, timeOfDay.Second, timeOfDay.Millisecond);
+                DateTime timeOfDay = TimeOnly.FromDateTime(GetNextDateTimeValue(TimeOfDayFormat)).ToDateTime();
 
                 int month = GetNextInt32Value();
 

src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.TransitionTime.cs

@@ -99,8 +99,7 @@ private static void ValidateTransitionTime(DateTime timeOfDay, int month, int we
                     throw new ArgumentOutOfRangeException(nameof(dayOfWeek), SR.ArgumentOutOfRange_DayOfWeek);
                 }
 
-                timeOfDay.GetDate(out int timeOfDayYear, out int timeOfDayMonth, out int timeOfDayDay);
-                if (timeOfDayYear != 1 || timeOfDayMonth != 1 || timeOfDayDay != 1 || (timeOfDay.Ticks % TimeSpan.TicksPerMillisecond != 0))
+                if (timeOfDay.Ticks >= TimeSpan.TicksPerDay || (ulong)timeOfDay.Ticks % TimeSpan.TicksPerMillisecond != 0)
                 {
                     throw new ArgumentException(SR.Argument_DateTimeHasTicks, nameof(timeOfDay));
                 }

src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.cs

@@ -711,8 +711,8 @@ public static DateTimeOffset ConvertTime(DateTimeOffset dateTimeOffset, TimeZone
             long ticks = utcDateTime.Ticks + destinationOffset.Ticks;
 
             return
-                ticks > DateTimeOffset.MaxValue.Ticks ? DateTimeOffset.MaxValue :
-                ticks < DateTimeOffset.MinValue.Ticks ? DateTimeOffset.MinValue :
+                ticks > DateTime.MaxTicks ? DateTimeOffset.MaxValue :
+                ticks < DateTime.MinTicks ? DateTimeOffset.MinValue :
                 new DateTimeOffset(ticks, destinationOffset);
         }
 
@@ -836,10 +836,6 @@ public static DateTime ConvertTimeToUtc(DateTime dateTime)
         /// </summary>
         internal static DateTime ConvertTimeToUtc(DateTime dateTime, TimeZoneInfoOptions flags)
         {
-            if (dateTime.Kind == DateTimeKind.Utc)
-            {
-                return dateTime;
-            }
             CachedData cachedData = s_cachedData;
             return ConvertTime(dateTime, cachedData.Local, s_utcTimeZone, flags, cachedData);
         }
@@ -1298,8 +1294,8 @@ private DateTime ConvertToFromUtc(DateTime dateTime, TimeSpan daylightDelta, Tim
             long ticks = dateTime.Ticks + offset.Ticks;
 
             return
-                ticks > DateTime.MaxValue.Ticks ? DateTime.MaxValue :
-                ticks < DateTime.MinValue.Ticks ? DateTime.MinValue :
+                ticks > DateTime.MaxTicks ? DateTime.MaxValue :
+                ticks < DateTime.MinTicks ? DateTime.MinValue :
                 new DateTime(ticks);
         }
 
@@ -1312,17 +1308,17 @@ private static DateTime ConvertUtcToTimeZone(long ticks, TimeZoneInfo destinatio
         {
             // used to calculate the UTC offset in the destinationTimeZone
             DateTime utcConverted =
-                ticks > DateTime.MaxValue.Ticks ? DateTime.MaxValue :
-                ticks < DateTime.MinValue.Ticks ? DateTime.MinValue :
+                ticks > DateTime.MaxTicks ? DateTime.MaxValue :
+                ticks < DateTime.MinTicks ? DateTime.MinValue :
                 new DateTime(ticks);
 
             // verify the time is between MinValue and MaxValue in the new time zone
             TimeSpan offset = GetUtcOffsetFromUtc(utcConverted, destinationTimeZone, out isAmbiguousLocalDst);
             ticks += offset.Ticks;
 
             return
-                ticks > DateTime.MaxValue.Ticks ? DateTime.MaxValue :
-                ticks < DateTime.MinValue.Ticks ? DateTime.MinValue :
+                ticks > DateTime.MaxTicks ? DateTime.MaxValue :
+                ticks < DateTime.MinTicks ? DateTime.MinValue :
                 new DateTime(ticks);
         }
 
@@ -1373,11 +1369,11 @@ private static bool GetIsDaylightSavings(DateTime time, AdjustmentRule rule, Day
                 // startTime and endTime represent the period from either the start of
                 // DST to the end and ***includes*** the potentially overlapped times
                 startTime = rule.IsStartDateMarkerForBeginningOfYear() ?
-                    new DateTime(daylightTime.Start.Year, 1, 1, 0, 0, 0) :
+                    new DateTime(daylightTime.Start.Year, 1, 1) :
                     daylightTime.Start + daylightTime.Delta;
 
                 endTime = rule.IsEndDateMarkerForEndOfYear() ?
-                    new DateTime(daylightTime.End.Year + 1, 1, 1, 0, 0, 0).AddTicks(-1) :
+                    new DateTime(daylightTime.End.Year + 1, 1, 1).AddTicks(-1) :
                     daylightTime.End;
             }
             else
@@ -1402,11 +1398,11 @@ private static bool GetIsDaylightSavings(DateTime time, AdjustmentRule rule, Day
                 bool invalidAtStart = rule.DaylightDelta > TimeSpan.Zero;
 
                 startTime = rule.IsStartDateMarkerForBeginningOfYear() ?
-                    new DateTime(daylightTime.Start.Year, 1, 1, 0, 0, 0) :
+                    new DateTime(daylightTime.Start.Year, 1, 1) :
                     daylightTime.Start + (invalidAtStart ? rule.DaylightDelta : TimeSpan.Zero); /* FUTURE: - rule.StandardDelta; */
 
                 endTime = rule.IsEndDateMarkerForEndOfYear() ?
-                    new DateTime(daylightTime.End.Year + 1, 1, 1, 0, 0, 0).AddTicks(-1) :
+                    new DateTime(daylightTime.End.Year + 1, 1, 1).AddTicks(-1) :
                     daylightTime.End + (invalidAtStart ? -rule.DaylightDelta : TimeSpan.Zero);
             }
 
@@ -1484,15 +1480,15 @@ private static bool GetIsDaylightSavingsFromUtc(DateTime time, int year, TimeSpa
             bool ignoreYearAdjustment = false;
             TimeSpan dstStartOffset = zone.GetDaylightSavingsStartOffsetFromUtc(utc, rule, ruleIndex);
             DateTime startTime;
-            if (rule.IsStartDateMarkerForBeginningOfYear() && daylightTime.Start.Year > DateTime.MinValue.Year)
+            if (rule.IsStartDateMarkerForBeginningOfYear() && daylightTime.Start.Year is > 1 and int startYear)
             {
-                if (TryGetStartOfDstIfYearEndWithDst(daylightTime.Start.Year - 1, utc, zone, out startTime))
+                if (TryGetStartOfDstIfYearEndWithDst(startYear - 1, utc, zone, out startTime))
                 {
                     ignoreYearAdjustment = true;
                 }
                 else
                 {
-                    startTime = new DateTime(daylightTime.Start.Year, 1, 1, 0, 0, 0) - dstStartOffset;
+                    startTime = new DateTime(startYear, 1, 1) - dstStartOffset;
                 }
             }
             else
@@ -1502,15 +1498,15 @@ private static bool GetIsDaylightSavingsFromUtc(DateTime time, int year, TimeSpa
 
             TimeSpan dstEndOffset = GetDaylightSavingsEndOffsetFromUtc(utc, rule);
             DateTime endTime;
-            if (rule.IsEndDateMarkerForEndOfYear() && daylightTime.End.Year < DateTime.MaxValue.Year)
+            if (rule.IsEndDateMarkerForEndOfYear() && daylightTime.End.Year is < 9999 and int endYear)
             {
-                if (TryGetEndOfDstIfYearStartWithDst(daylightTime.End.Year + 1, utc, zone, out endTime))
+                if (TryGetEndOfDstIfYearStartWithDst(endYear + 1, utc, zone, out endTime))
                 {
                     ignoreYearAdjustment = true;
                 }
                 else
                 {
-                    endTime = new DateTime(daylightTime.End.Year + 1, 1, 1, 0, 0, 0).AddTicks(-1) - dstEndOffset;
+                    endTime = new DateTime(endYear + 1, 1, 1).AddTicks(-1) - dstEndOffset;
                 }
             }
             else
@@ -2190,8 +2186,8 @@ private static void ValidateTimeZoneInfo(string id, TimeSpan baseUtcOffset, Adju
             }
         }
 
-        private static readonly TimeSpan MaxOffset = TimeSpan.FromHours(14.0);
-        private static readonly TimeSpan MinOffset = -MaxOffset;
+        private static TimeSpan MaxOffset => TimeSpan.FromHours(14);
+        private static TimeSpan MinOffset => TimeSpan.FromHours(-14);
 
         /// <summary>
         /// Helper function that validates the TimeSpan is within +/- 14.0 hours