// Licensed to the .NET Foundation under one or more agreements.

// The .NET Foundation licenses this file to you under the MIT license.

using System.ComponentModel;

using System.Diagnostics;

using System.Diagnostics.CodeAnalysis;

using System.Globalization;

using System.Numerics;

using System.Runtime.CompilerServices;

using System.Runtime.InteropServices;

using System.Runtime.Serialization;

using System.Runtime.Versioning;

namespace System

{

// This value type represents a date and time. Every DateTime

// object has a private field (Ticks) of type Int64 that stores the

// date and time as the number of 100 nanosecond intervals since

// 12:00 AM January 1, year 1 A.D. in the proleptic Gregorian Calendar.

//

// Starting from V2.0, DateTime also stored some context about its time

// zone in the form of a 3-state value representing Unspecified, Utc or

// Local. This is stored in the two top bits of the 64-bit numeric value

// with the remainder of the bits storing the tick count. This information

// is only used during time zone conversions and is not part of the

// identity of the DateTime. Thus, operations like Compare and Equals

// ignore this state. This is to stay compatible with earlier behavior

// and performance characteristics and to avoid forcing people into dealing

// with the effects of daylight savings. Note, that this has little effect

// on how the DateTime works except in a context where its specific time

// zone is needed, such as during conversions and some parsing and formatting

// cases.

//

// There is also 4th state stored that is a special type of Local value that

// is used to avoid data loss when round-tripping between local and UTC time.

// See below for more information on this 4th state, although it is

// effectively hidden from most users, who just see the 3-state DateTimeKind

// enumeration.

//

// For compatibility, DateTime does not serialize the Kind data when used in

// binary serialization.

//

// For a description of various calendar issues, look at

//

//

[StructLayout(LayoutKind.Auto)]

[Serializable]

[TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]

public readonly partial struct DateTime

: IComparable,

ISpanFormattable,

IConvertible,

IComparable<DateTime>,

IEquatable<DateTime>,

ISerializable,

ISpanParsable<DateTime>,

IUtf8SpanFormattable

{

// Number of days in a non-leap year

private const int DaysPerYear = 365;

// Number of days in 4 years

private const int DaysPer4Years = DaysPerYear * 4 + 1; // 1461

// Number of days in 100 years

private const int DaysPer100Years = DaysPer4Years * 25 - 1; // 36524

// Number of days in 400 years

private const int DaysPer400Years = DaysPer100Years * 4 + 1; // 146097

// Number of days from 1/1/0001 to 12/31/1600

private const int DaysTo1601 = DaysPer400Years * 4; // 584388

// Number of days from 1/1/0001 to 12/30/1899

private const int DaysTo1899 = DaysPer400Years * 4 + DaysPer100Years * 3 - 367;

// Number of days from 1/1/0001 to 12/31/1969

internal const int DaysTo1970 = DaysPer400Years * 4 + DaysPer100Years * 3 + DaysPer4Years * 17 + DaysPerYear; // 719,162

// Number of days from 1/1/0001 to 12/31/9999

internal const int DaysTo10000 = DaysPer400Years * 25 - 366; // 3652059

internal const long MinTicks = 0;

internal const long MaxTicks = DaysTo10000 * TimeSpan.TicksPerDay - 1;

private const long MaxMicroseconds = MaxTicks / TimeSpan.TicksPerMicrosecond;

private const long MaxMillis = MaxTicks / TimeSpan.TicksPerMillisecond;

private const long MaxSeconds = MaxTicks / TimeSpan.TicksPerSecond;

private const long MaxMinutes = MaxTicks / TimeSpan.TicksPerMinute;

private const long MaxHours = MaxTicks / TimeSpan.TicksPerHour;

private const long MaxDays = (long)DaysTo10000 - 1;

internal const long UnixEpochTicks = DaysTo1970 * TimeSpan.TicksPerDay;

private const long FileTimeOffset = DaysTo1601 * TimeSpan.TicksPerDay;

private const long DoubleDateOffset = DaysTo1899 * TimeSpan.TicksPerDay;

// The minimum OA date is 0100/01/01 (Note it's year 100).

// The maximum OA date is 9999/12/31

private const long OADateMinAsTicks = (DaysPer100Years - DaysPerYear) * TimeSpan.TicksPerDay;

// All OA dates must be greater than (not >=) OADateMinAsDouble

private const double OADateMinAsDouble = -657435.0;

// All OA dates must be less than (not <=) OADateMaxAsDouble

private const double OADateMaxAsDouble = 2958466.0;

// Euclidean Affine Functions Algorithm (EAF) constants

// Constants used for fast calculation of following subexpressions

// x / DaysPer4Years

// x % DaysPer4Years / 4

private const uint EafMultiplier = (uint)(((1UL << 32) + DaysPer4Years - 1) / DaysPer4Years); // 2,939,745

private const uint EafDivider = EafMultiplier * 4; // 11,758,980

private const ulong TicksPer6Hours = TimeSpan.TicksPerHour * 6;

private const int March1BasedDayOfNewYear = 306; // Days between March 1 and January 1

internal static ReadOnlySpan<uint> DaysToMonth365 => [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365];

internal static ReadOnlySpan<uint> DaysToMonth366 => [0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366];

private static ReadOnlySpan<byte> DaysInMonth365 => [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];

private static ReadOnlySpan<byte> DaysInMonth366 => [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];

public static readonly DateTime MinValue;

public static readonly DateTime MaxValue = new DateTime(MaxTicks, DateTimeKind.Unspecified);

public static readonly DateTime UnixEpoch = new DateTime(UnixEpochTicks, DateTimeKind.Utc);

private const ulong TicksMask = 0x3FFFFFFFFFFFFFFF;

private const ulong FlagsMask = 0xC000000000000000;

private const long TicksCeiling = 0x4000000000000000;

internal const ulong KindUtc = 0x4000000000000000;

private const ulong KindLocal = 0x8000000000000000;

private const ulong KindLocalAmbiguousDst = 0xC000000000000000;

private const int KindShift = 62;

private const string TicksField = "ticks"; // Do not rename (binary serialization)

private const string DateDataField = "dateData"; // Do not rename (binary serialization)

// The data is stored as an unsigned 64-bit integer

// Bits 01-62: The value of 100-nanosecond ticks where 0 represents 1/1/0001 12:00am, up until the value

// 12/31/9999 23:59:59.9999999

// Bits 63-64: A four-state value that describes the DateTimeKind value of the date time, with a 2nd

// value for the rare case where the date time is local, but is in an overlapped daylight

// savings time hour and it is in daylight savings time. This allows distinction of these

// otherwise ambiguous local times and prevents data loss when round tripping from Local to

// UTC time.

internal readonly ulong _dateData;

// Constructs a DateTime from a tick count. The ticks

// argument specifies the date as the number of 100-nanosecond intervals

// that have elapsed since 1/1/0001 12:00am.

//

public DateTime(long ticks)

{

if ((ulong)ticks > MaxTicks) ThrowTicksOutOfRange();

_dateData = (ulong)ticks;

}

private DateTime(ulong dateData)

{

Debug.Assert((dateData & TicksMask) <= MaxTicks);

_dateData = dateData;

}

internal static DateTime CreateUnchecked(long ticks) => new DateTime((ulong)ticks);

public DateTime(long ticks, DateTimeKind kind)

{

if ((ulong)ticks > MaxTicks) ThrowTicksOutOfRange();

if ((uint)kind > (uint)DateTimeKind.Local) ThrowInvalidKind();

_dateData = (ulong)ticks | ((ulong)(uint)kind << KindShift);

}

/// <summary>

/// Initializes a new instance of the <see cref="DateTime"/> structure to the specified <see cref="DateOnly"/> and <see cref="TimeOnly"/>.

/// The new instance will have the <see cref="DateTimeKind.Unspecified"/> kind.

/// </summary>

/// <param name="date">

/// The date part.

/// </param>

/// <param name="time">

/// The time part.

/// </param>

public DateTime(DateOnly date, TimeOnly time)

{

_dateData = (ulong)(date.DayNumber * TimeSpan.TicksPerDay + time.Ticks);

}

/// <summary>

/// Initializes a new instance of the <see cref="DateTime"/> structure to the specified <see cref="DateOnly"/> and <see cref="TimeOnly"/> respecting a <see cref="DateTimeKind"/>.

/// </summary>

/// <param name="date">

/// The date part.

/// </param>

/// <param name="time">

/// The time part.

/// </param>

/// <param name="kind">

/// One of the enumeration values that indicates whether <paramref name="date"/>

/// and <paramref name="time"/> specify a local time, Coordinated Universal Time (UTC), or neither.

/// </param>

public DateTime(DateOnly date, TimeOnly time, DateTimeKind kind)

{

if ((uint)kind > (uint)DateTimeKind.Local) ThrowInvalidKind();

_dateData = (ulong)(date.DayNumber * TimeSpan.TicksPerDay + time.Ticks) | ((ulong)(uint)kind << KindShift);

}

internal DateTime(long ticks, DateTimeKind kind, bool isAmbiguousDst)

{

if ((ulong)ticks > MaxTicks) ThrowTicksOutOfRange();

Debug.Assert(kind == DateTimeKind.Local, "Internal Constructor is for local times only");

_dateData = ((ulong)ticks | (isAmbiguousDst ? KindLocalAmbiguousDst : KindLocal));

}

private static void ThrowTicksOutOfRange() => throw new ArgumentOutOfRangeException("ticks", SR.ArgumentOutOfRange_DateTimeBadTicks);

private static void ThrowInvalidKind() => throw new ArgumentException(SR.Argument_InvalidDateTimeKind, "kind");

internal static void ThrowMillisecondOutOfRange() => throw new ArgumentOutOfRangeException("millisecond", SR.Format(SR.ArgumentOutOfRange_Range, 0, TimeSpan.MillisecondsPerSecond - 1));

internal static void ThrowMicrosecondOutOfRange() => throw new ArgumentOutOfRangeException("microsecond", SR.Format(SR.ArgumentOutOfRange_Range, 0, TimeSpan.MicrosecondsPerMillisecond - 1));

private static void ThrowDateArithmetic(int param) => throw new ArgumentOutOfRangeException(param switch { 0 => "value", 1 => "t", _ => "months" }, SR.ArgumentOutOfRange_DateArithmetic);

private static void ThrowAddOutOfRange() => throw new ArgumentOutOfRangeException("value", SR.ArgumentOutOfRange_AddValue);

// Constructs a DateTime from a given year, month, and day. The

// time-of-day of the resulting DateTime is always midnight.

//

public DateTime(int year, int month, int day)

{

_dateData = DateToTicks(year, month, day);

}

// Constructs a DateTime from a given year, month, and day for

// the specified calendar. The

// time-of-day of the resulting DateTime is always midnight.

//

public DateTime(int year, int month, int day, Calendar calendar)

: this(year, month, day, 0, 0, 0, calendar)

{

}

/// <summary>

/// Initializes a new instance of the <see cref="DateTime"/> structure to the specified year, month, day, hour, minute, second,

/// millisecond, and Coordinated Universal Time (UTC) or local time for the specified calendar.

/// </summary>

/// <param name="year">The year (1 through the number of years in <paramref name="calendar"/>).</param>

/// <param name="month">The month (1 through the number of months in <paramref name="calendar"/>).</param>

/// <param name="day">The day (1 through the number of days in <paramref name="month"/>).</param>

/// <param name="hour">The hours (0 through 23).</param>

/// <param name="minute">The minutes (0 through 59).</param>

/// <param name="second">The seconds (0 through 59).</param>

/// <param name="millisecond">The milliseconds (0 through 999).</param>

/// <param name="calendar">The calendar that is used to interpret <paramref name="year"/>, <paramref name="month"/>, and <paramref name="day"/>.</param>

/// <param name="kind">

/// One of the enumeration values that indicates whether <paramref name="year"/>, <paramref name="month"/>, <paramref name="day"/>,

/// <paramref name="hour"/>, <paramref name="minute"/>, <paramref name="second"/>, and <paramref name="millisecond"/>

/// specify a local time, Coordinated Universal Time (UTC), or neither.</param>

/// <exception cref="ArgumentNullException">

/// <paramref name="calendar"/> is <see langword="null"/>

/// </exception>

/// <exception cref="ArgumentOutOfRangeException">

/// <paramref name="year"/> is not in the range supported by <paramref name="calendar"/>.

///

/// -or-

///

/// <paramref name="month"/> is less than 1 or greater than the number of months in <paramref name="calendar"/>.

///

/// -or-

///

/// <paramref name="day"/> is less than 1 or greater than the number of days in <paramref name="month"/>.

///

/// -or-

///

/// <paramref name="hour"/> is less than 0 or greater than 23.

///

/// -or-

///

/// <paramref name="minute"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="second"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="millisecond"/> is less than 0 or greater than 999.

/// </exception>

/// <exception cref="ArgumentException">

/// <paramref name="kind"/> is not one of the <see cref="DateTimeKind"/> values.

/// </exception>

/// <remarks>

/// The allowable values for <paramref name="year"/>, <paramref name="month"/>, and <paramref name="day"/> parameters

/// depend on the <paramref name="calendar"/> parameter. An exception is thrown if the specified date and time cannot

/// be expressed using <paramref name="calendar"/>.

///

/// For applications in which portability of date and time data or a limited degree of time zone awareness is important,

/// you can use the corresponding <see cref="DateTimeOffset"/> constructor.

/// </remarks>

public DateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, Calendar calendar, DateTimeKind kind)

{

ArgumentNullException.ThrowIfNull(calendar);

if ((uint)millisecond >= TimeSpan.MillisecondsPerSecond) ThrowMillisecondOutOfRange();

if ((uint)kind > (uint)DateTimeKind.Local) ThrowInvalidKind();

if (second != 60 || !SystemSupportsLeapSeconds)

{

ulong ticks = calendar.ToDateTime(year, month, day, hour, minute, second, millisecond).UTicks;

_dateData = ticks | ((ulong)(uint)kind << KindShift);

}

else

{

_dateData = WithLeapSecond(calendar, year, month, day, hour, minute, millisecond, kind);

}

}

[MethodImpl(MethodImplOptions.NoInlining)]

private static ulong WithLeapSecond(Calendar calendar, int year, int month, int day, int hour, int minute, int millisecond, DateTimeKind kind)

{

// if we have a leap second, then we adjust it to 59 so that DateTime will consider it the last in the specified minute.

return ValidateLeapSecond(new DateTime(year, month, day, hour, minute, 59, millisecond, calendar, kind));

}

// Constructs a DateTime from a given year, month, day, hour,

// minute, and second.

//

public DateTime(int year, int month, int day, int hour, int minute, int second)

{

ulong ticks = DateToTicks(year, month, day);

if (second != 60 || !SystemSupportsLeapSeconds)

{

_dateData = ticks + TimeToTicks(hour, minute, second);

}

else

{

_dateData = WithLeapSecond(ticks, hour, minute);

}

}

[MethodImpl(MethodImplOptions.NoInlining)]

private static ulong WithLeapSecond(ulong ticks, int hour, int minute)

{

// if we have a leap second, then we adjust it to 59 so that DateTime will consider it the last in the specified minute.

// codeql[cs/leap-year/unsafe-date-construction-from-two-elements] - DateTime is constructed using the user specified values, not a combination of different sources. It would be intentional to throw if an invalid combination occurred.

return ValidateLeapSecond(new DateTime(ticks + TimeToTicks(hour, minute, 59)));

}

public DateTime(int year, int month, int day, int hour, int minute, int second, DateTimeKind kind)

{

if ((uint)kind > (uint)DateTimeKind.Local) ThrowInvalidKind();

ulong ticks = DateToTicks(year, month, day) | ((ulong)(uint)kind << KindShift);

if (second != 60 || !SystemSupportsLeapSeconds)

{

_dateData = ticks + TimeToTicks(hour, minute, second);

}

else

{

_dateData = WithLeapSecond(ticks, hour, minute);

}

}

// Constructs a DateTime from a given year, month, day, hour,

// minute, and second for the specified calendar.

//

public DateTime(int year, int month, int day, int hour, int minute, int second, Calendar calendar)

{

ArgumentNullException.ThrowIfNull(calendar);

if (second != 60 || !SystemSupportsLeapSeconds)

{

_dateData = calendar.ToDateTime(year, month, day, hour, minute, second, 0).UTicks;

}

else

{

_dateData = WithLeapSecond(calendar, year, month, day, hour, minute);

}

}

[MethodImpl(MethodImplOptions.NoInlining)]

private static ulong WithLeapSecond(Calendar calendar, int year, int month, int day, int hour, int minute)

{

// if we have a leap second, then we adjust it to 59 so that DateTime will consider it the last in the specified minute.

return ValidateLeapSecond(new DateTime(year, month, day, hour, minute, 59, calendar));

}

/// <summary>

/// Initializes a new instance of the <see cref="DateTime"/> structure to the specified year, month, day, hour, minute, second,

/// millisecond, and Coordinated Universal Time (UTC) or local time for the specified calendar.

/// </summary>

/// <param name="year">The year (1 through 9999).</param>

/// <param name="month">The month (1 through 12).</param>

/// <param name="day">The day (1 through the number of days in <paramref name="month"/>).</param>

/// <param name="hour">The hours (0 through 23).</param>

/// <param name="minute">The minutes (0 through 59).</param>

/// <param name="second">The seconds (0 through 59).</param>

/// <param name="millisecond">The milliseconds (0 through 999).</param>

/// <exception cref="ArgumentOutOfRangeException">

/// <paramref name="year"/> is less than 1 or greater than 9999.

///

/// -or-

///

/// <paramref name="month"/> is less than 1 or greater than 12.

///

/// -or-

///

/// <paramref name="day"/> is less than 1 or greater than the number of days in <paramref name="month"/>.

///

/// -or-

///

/// <paramref name="hour"/> is less than 0 or greater than 23.

///

/// -or-

///

/// <paramref name="minute"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="second"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="millisecond"/> is less than 0 or greater than 999.

/// </exception>

/// <remarks>

/// This constructor interprets <paramref name="year"/>, <paramref name="month"/> and <paramref name="day"/> as a year, month and day

/// in the Gregorian calendar. To instantiate a <see cref="DateTime"/> value by using the year, month and day in another calendar, call

/// the <see cref="DateTime(int, int, int, int, int, int, int, int, Calendar)"/> constructor.

///

/// The <see cref="Kind"/> property is initialized to <see cref="DateTimeKind.Unspecified"/>.

///

/// For applications in which portability of date and time data or a limited degree of time zone awareness is important,

/// you can use the corresponding <see cref="DateTimeOffset"/> constructor.

/// </remarks>

public DateTime(int year, int month, int day, int hour, int minute, int second, int millisecond)

: this(year, month, day, hour, minute, second)

{

if ((uint)millisecond >= TimeSpan.MillisecondsPerSecond) ThrowMillisecondOutOfRange();

_dateData += (uint)millisecond * (uint)TimeSpan.TicksPerMillisecond;

}

/// <summary>

/// Initializes a new instance of the <see cref="DateTime"/> structure to the specified year, month, day, hour, minute, second,

/// millisecond, and Coordinated Universal Time (UTC) or local time for the specified calendar.

/// </summary>

/// <param name="year">The year (1 through 9999).</param>

/// <param name="month">The month (1 through 12).</param>

/// <param name="day">The day (1 through the number of days in <paramref name="month"/>).</param>

/// <param name="hour">The hours (0 through 23).</param>

/// <param name="minute">The minutes (0 through 59).</param>

/// <param name="second">The seconds (0 through 59).</param>

/// <param name="millisecond">The milliseconds (0 through 999).</param>

/// <param name="kind">

/// One of the enumeration values that indicates whether <paramref name="year"/>, <paramref name="month"/>, <paramref name="day"/>,

/// <paramref name="hour"/>, <paramref name="minute"/>, <paramref name="second"/>, and <paramref name="millisecond"/>

/// specify a local time, Coordinated Universal Time (UTC), or neither.</param>

/// <exception cref="ArgumentOutOfRangeException">

/// <paramref name="year"/> is less than 1 or greater than 9999.

///

/// -or-

///

/// <paramref name="month"/> is less than 1 or greater than 12.

///

/// -or-

///

/// <paramref name="day"/> is less than 1 or greater than the number of days in <paramref name="month"/>.

///

/// -or-

///

/// <paramref name="hour"/> is less than 0 or greater than 23.

///

/// -or-

///

/// <paramref name="minute"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="second"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="millisecond"/> is less than 0 or greater than 999.

/// </exception>

/// <exception cref="ArgumentException">

/// <paramref name="kind"/> is not one of the <see cref="DateTimeKind"/> values.

/// </exception>

/// <remarks>

/// This constructor interprets <paramref name="year"/>, <paramref name="month"/> and <paramref name="day"/> as a year, month and day

/// in the Gregorian calendar. To instantiate a <see cref="DateTime"/> value by using the year, month and day in another calendar, call

/// the <see cref="DateTime(int, int, int, int, int, int, int, int, Calendar, DateTimeKind)"/> constructor.

///

/// For applications in which portability of date and time data or a limited degree of time zone awareness is important,

/// you can use the corresponding <see cref="DateTimeOffset"/> constructor.

/// </remarks>

public DateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, DateTimeKind kind)

: this(year, month, day, hour, minute, second, kind)

{

if ((uint)millisecond >= TimeSpan.MillisecondsPerSecond) ThrowMillisecondOutOfRange();

_dateData += (uint)millisecond * (uint)TimeSpan.TicksPerMillisecond;

}

/// <summary>

/// Initializes a new instance of the <see cref="DateTime"/> structure to the specified year, month, day, hour, minute, second,

/// millisecond, and Coordinated Universal Time (UTC) or local time for the specified calendar.

/// </summary>

/// <param name="year">The year (1 through the number of years in <paramref name="calendar"/>).</param>

/// <param name="month">The month (1 through the number of months in <paramref name="calendar"/>).</param>

/// <param name="day">The day (1 through the number of days in <paramref name="month"/>).</param>

/// <param name="hour">The hours (0 through 23).</param>

/// <param name="minute">The minutes (0 through 59).</param>

/// <param name="second">The seconds (0 through 59).</param>

/// <param name="millisecond">The milliseconds (0 through 999).</param>

/// <param name="calendar">The calendar that is used to interpret <paramref name="year"/>, <paramref name="month"/>, and <paramref name="day"/>.</param>

/// <exception cref="ArgumentNullException">

/// <paramref name="calendar"/> is <see langword="null"/>

/// </exception>

/// <exception cref="ArgumentOutOfRangeException">

/// <paramref name="year"/> is not in the range supported by <paramref name="calendar"/>.

///

/// -or-

///

/// <paramref name="month"/> is less than 1 or greater than the number of months in <paramref name="calendar"/>.

///

/// -or-

///

/// <paramref name="day"/> is less than 1 or greater than the number of days in <paramref name="month"/>.

///

/// -or-

///

/// <paramref name="hour"/> is less than 0 or greater than 23.

///

/// -or-

///

/// <paramref name="minute"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="second"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="millisecond"/> is less than 0 or greater than 999.

/// </exception>

/// <remarks>

/// The allowable values for <paramref name="year"/>, <paramref name="month"/>, and <paramref name="day"/> parameters

/// depend on the <paramref name="calendar"/> parameter. An exception is thrown if the specified date and time cannot

/// be expressed using <paramref name="calendar"/>.

///

/// For applications in which portability of date and time data or a limited degree of time zone awareness is important,

/// you can use the corresponding <see cref="DateTimeOffset"/> constructor.

/// </remarks>

public DateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, Calendar calendar)

{

ArgumentNullException.ThrowIfNull(calendar);

if (second != 60 || !SystemSupportsLeapSeconds)

{

_dateData = calendar.ToDateTime(year, month, day, hour, minute, second, millisecond).UTicks;

}

else

{

_dateData = WithLeapSecond(calendar, year, month, day, hour, minute, millisecond);

}

}

[MethodImpl(MethodImplOptions.NoInlining)]

private static ulong WithLeapSecond(Calendar calendar, int year, int month, int day, int hour, int minute, int millisecond)

{

// if we have a leap second, then we adjust it to 59 so that DateTime will consider it the last in the specified minute.

return ValidateLeapSecond(new DateTime(year, month, day, hour, minute, 59, millisecond, calendar));

}

/// <summary>

/// Initializes a new instance of the <see cref="DateTime"/> structure to the specified year, month, day, hour, minute, second,

/// millisecond, and Coordinated Universal Time (UTC) or local time for the specified calendar.

/// </summary>

/// <param name="year">The year (1 through 9999).</param>

/// <param name="month">The month (1 through 12).</param>

/// <param name="day">The day (1 through the number of days in <paramref name="month"/>).</param>

/// <param name="hour">The hours (0 through 23).</param>

/// <param name="minute">The minutes (0 through 59).</param>

/// <param name="second">The seconds (0 through 59).</param>

/// <param name="millisecond">The milliseconds (0 through 999).</param>

/// <param name="microsecond">The microseconds (0 through 999).</param>

/// <exception cref="ArgumentOutOfRangeException">

/// <paramref name="year"/> is less than 1 or greater than 9999.

///

/// -or-

///

/// <paramref name="month"/> is less than 1 or greater than 12.

///

/// -or-

///

/// <paramref name="day"/> is less than 1 or greater than the number of days in <paramref name="month"/>.

///

/// -or-

///

/// <paramref name="hour"/> is less than 0 or greater than 23.

///

/// -or-

///

/// <paramref name="minute"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="second"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="millisecond"/> is less than 0 or greater than 999.

///

/// -or-

///

/// <paramref name="microsecond"/> is less than 0 or greater than 999.

/// </exception>

/// <remarks>

/// This constructor interprets <paramref name="year"/>, <paramref name="month"/> and <paramref name="day"/> as a year, month and day

/// in the Gregorian calendar. To instantiate a <see cref="DateTime"/> value by using the year, month and day in another calendar, call

/// the <see cref="DateTime(int, int, int, int, int, int, int, int, Calendar)"/> constructor.

///

/// The <see cref="Kind"/> property is initialized to <see cref="DateTimeKind.Unspecified"/>.

///

/// For applications in which portability of date and time data or a limited degree of time zone awareness is important,

/// you can use the corresponding <see cref="DateTimeOffset"/> constructor.

/// </remarks>

public DateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, int microsecond)

: this(year, month, day, hour, minute, second, millisecond, microsecond, DateTimeKind.Unspecified)

{

}

/// <summary>

/// Initializes a new instance of the <see cref="DateTime"/> structure to the specified year, month, day, hour, minute, second,

/// millisecond, and Coordinated Universal Time (UTC) or local time for the specified calendar.

/// </summary>

/// <param name="year">The year (1 through 9999).</param>

/// <param name="month">The month (1 through 12).</param>

/// <param name="day">The day (1 through the number of days in <paramref name="month"/>).</param>

/// <param name="hour">The hours (0 through 23).</param>

/// <param name="minute">The minutes (0 through 59).</param>

/// <param name="second">The seconds (0 through 59).</param>

/// <param name="millisecond">The milliseconds (0 through 999).</param>

/// <param name="microsecond">The microseconds (0 through 999).</param>

/// <param name="kind">

/// One of the enumeration values that indicates whether <paramref name="year"/>, <paramref name="month"/>, <paramref name="day"/>,

/// <paramref name="hour"/>, <paramref name="minute"/>, <paramref name="second"/>, and <paramref name="millisecond"/>

/// specify a local time, Coordinated Universal Time (UTC), or neither.</param>

/// <exception cref="ArgumentOutOfRangeException">

/// <paramref name="year"/> is less than 1 or greater than 9999.

///

/// -or-

///

/// <paramref name="month"/> is less than 1 or greater than 12.

///

/// -or-

///

/// <paramref name="day"/> is less than 1 or greater than the number of days in <paramref name="month"/>.

///

/// -or-

///

/// <paramref name="hour"/> is less than 0 or greater than 23.

///

/// -or-

///

/// <paramref name="minute"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="second"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="millisecond"/> is less than 0 or greater than 999.

///

/// -or-

///

/// <paramref name="microsecond"/> is less than 0 or greater than 999.

/// </exception>

/// <exception cref="ArgumentException">

/// <paramref name="kind"/> is not one of the <see cref="DateTimeKind"/> values.

/// </exception>

/// <remarks>

/// This constructor interprets <paramref name="year"/>, <paramref name="month"/> and <paramref name="day"/> as a year, month and day

/// in the Gregorian calendar. To instantiate a <see cref="DateTime"/> value by using the year, month and day in another calendar, call

/// the <see cref="DateTime(int, int, int, int, int, int, int, int, Calendar, DateTimeKind)"/> constructor.

///

/// For applications in which portability of date and time data or a limited degree of time zone awareness is important,

/// you can use the corresponding <see cref="DateTimeOffset"/> constructor.

/// </remarks>

public DateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, int microsecond, DateTimeKind kind)

: this(year, month, day, hour, minute, second, millisecond, kind)

{

if ((uint)microsecond >= TimeSpan.MicrosecondsPerMillisecond) ThrowMicrosecondOutOfRange();

_dateData += (uint)microsecond * (uint)TimeSpan.TicksPerMicrosecond;

}

/// <summary>

/// Initializes a new instance of the <see cref="DateTime"/> structure to the specified year, month, day, hour, minute, second,

/// millisecond, and Coordinated Universal Time (UTC) or local time for the specified calendar.

/// </summary>

/// <param name="year">The year (1 through the number of years in <paramref name="calendar"/>).</param>

/// <param name="month">The month (1 through the number of months in <paramref name="calendar"/>).</param>

/// <param name="day">The day (1 through the number of days in <paramref name="month"/>).</param>

/// <param name="hour">The hours (0 through 23).</param>

/// <param name="minute">The minutes (0 through 59).</param>

/// <param name="second">The seconds (0 through 59).</param>

/// <param name="millisecond">The milliseconds (0 through 999).</param>

/// <param name="microsecond">The microseconds (0 through 999).</param>

/// <param name="calendar">The calendar that is used to interpret <paramref name="year"/>, <paramref name="month"/>, and <paramref name="day"/>.</param>

/// <exception cref="ArgumentNullException">

/// <paramref name="calendar"/> is <see langword="null"/>

/// </exception>

/// <exception cref="ArgumentOutOfRangeException">

/// <paramref name="year"/> is not in the range supported by <paramref name="calendar"/>.

///

/// -or-

///

/// <paramref name="month"/> is less than 1 or greater than the number of months in <paramref name="calendar"/>.

///

/// -or-

///

/// <paramref name="day"/> is less than 1 or greater than the number of days in <paramref name="month"/>.

///

/// -or-

///

/// <paramref name="hour"/> is less than 0 or greater than 23.

///

/// -or-

///

/// <paramref name="minute"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="second"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="millisecond"/> is less than 0 or greater than 999.

///

/// -or-

///

/// <paramref name="microsecond"/> is less than 0 or greater than 999.

/// </exception>

/// <remarks>

/// The allowable values for <paramref name="year"/>, <paramref name="month"/>, and <paramref name="day"/> parameters

/// depend on the <paramref name="calendar"/> parameter. An exception is thrown if the specified date and time cannot

/// be expressed using <paramref name="calendar"/>.

///

/// For applications in which portability of date and time data or a limited degree of time zone awareness is important,

/// you can use the corresponding <see cref="DateTimeOffset"/> constructor.

/// </remarks>

public DateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, int microsecond, Calendar calendar)

: this(year, month, day, hour, minute, second, millisecond, microsecond, calendar, DateTimeKind.Unspecified)

{

}

/// <summary>

/// Initializes a new instance of the <see cref="DateTime"/> structure to the specified year, month, day, hour, minute, second,

/// millisecond, and Coordinated Universal Time (UTC) or local time for the specified calendar.

/// </summary>

/// <param name="year">The year (1 through the number of years in <paramref name="calendar"/>).</param>

/// <param name="month">The month (1 through the number of months in <paramref name="calendar"/>).</param>

/// <param name="day">The day (1 through the number of days in <paramref name="month"/>).</param>

/// <param name="hour">The hours (0 through 23).</param>

/// <param name="minute">The minutes (0 through 59).</param>

/// <param name="second">The seconds (0 through 59).</param>

/// <param name="millisecond">The milliseconds (0 through 999).</param>

/// <param name="microsecond">The microseconds (0 through 999).</param>

/// <param name="calendar">The calendar that is used to interpret <paramref name="year"/>, <paramref name="month"/>, and <paramref name="day"/>.</param>

/// <param name="kind">

/// One of the enumeration values that indicates whether <paramref name="year"/>, <paramref name="month"/>, <paramref name="day"/>,

/// <paramref name="hour"/>, <paramref name="minute"/>, <paramref name="second"/>, and <paramref name="millisecond"/>

/// specify a local time, Coordinated Universal Time (UTC), or neither.</param>

/// <exception cref="ArgumentNullException">

/// <paramref name="calendar"/> is <see langword="null"/>

/// </exception>

/// <exception cref="ArgumentOutOfRangeException">

/// <paramref name="year"/> is not in the range supported by <paramref name="calendar"/>.

///

/// -or-

///

/// <paramref name="month"/> is less than 1 or greater than the number of months in <paramref name="calendar"/>.

///

/// -or-

///

/// <paramref name="day"/> is less than 1 or greater than the number of days in <paramref name="month"/>.

///

/// -or-

///

/// <paramref name="hour"/> is less than 0 or greater than 23.

///

/// -or-

///

/// <paramref name="minute"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="second"/> is less than 0 or greater than 59.

///

/// -or-

///

/// <paramref name="millisecond"/> is less than 0 or greater than 999.

///

/// -or-

///

/// <paramref name="microsecond"/> is less than 0 or greater than 999.

/// </exception>

/// <exception cref="ArgumentException">

/// <paramref name="kind"/> is not one of the <see cref="DateTimeKind"/> values.

/// </exception>

/// <remarks>

/// The allowable values for <paramref name="year"/>, <paramref name="month"/>, and <paramref name="day"/> parameters

/// depend on the <paramref name="calendar"/> parameter. An exception is thrown if the specified date and time cannot

/// be expressed using <paramref name="calendar"/>.

///

/// For applications in which portability of date and time data or a limited degree of time zone awareness is important,

/// you can use the corresponding <see cref="DateTimeOffset"/> constructor.

/// </remarks>

public DateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, int microsecond, Calendar calendar, DateTimeKind kind)

: this(year, month, day, hour, minute, second, millisecond, calendar, kind)

{

if ((uint)microsecond >= TimeSpan.MicrosecondsPerMillisecond) ThrowMicrosecondOutOfRange();

_dateData += (uint)microsecond * (uint)TimeSpan.TicksPerMicrosecond;

}

internal static ulong ValidateLeapSecond(DateTime value)

{

if (!IsValidTimeWithLeapSeconds(value))

{

ThrowHelper.ThrowArgumentOutOfRange_BadHourMinuteSecond();

}

return value._dateData;

}

private DateTime(SerializationInfo info, StreamingContext context)

{

if (info == null) ThrowHelper.ThrowArgumentNullException(ExceptionArgument.info);

bool foundTicks = false;

// Get the data

SerializationInfoEnumerator enumerator = info.GetEnumerator();

while (enumerator.MoveNext())

{

switch (enumerator.Name)

{

case TicksField:

_dateData = (ulong)Convert.ToInt64(enumerator.Value, CultureInfo.InvariantCulture);

foundTicks = true;

continue;

case DateDataField:

_dateData = Convert.ToUInt64(enumerator.Value, CultureInfo.InvariantCulture);

goto foundData;

}

}

if (!foundTicks)

{

throw new SerializationException(SR.Serialization_MissingDateTimeData);

}

foundData:

if (UTicks > MaxTicks)

{

throw new SerializationException(SR.Serialization_DateTimeTicksOutOfRange);

}

}

private ulong UTicks => _dateData & TicksMask;

private ulong InternalKind => _dateData & FlagsMask;

// Returns the DateTime resulting from adding the given

// TimeSpan to this DateTime.

//

public DateTime Add(TimeSpan value)

{

return AddTicks(value._ticks);

}

[MethodImpl(MethodImplOptions.AggressiveInlining)]

private DateTime AddUnits(double value, long maxUnitCount, long ticksPerUnit)

{

if (Math.Abs(value) > maxUnitCount)

{

ThrowAddOutOfRange();

}

double integralPart = Math.Truncate(value);

double fractionalPart = value - integralPart;

long ticks = (long)(integralPart) * ticksPerUnit;

ticks += (long)(fractionalPart * ticksPerUnit);

return AddTicks(ticks);

}

/// <summary>

/// Returns a new <see cref="DateTime"/> that adds the specified number of days to the value of this instance.

/// </summary>

/// <param name="value">A number of whole and fractional days. The value parameter can be negative or positive.</param>

/// <returns>

/// An object whose value is the sum of the date and time represented by this instance and the number of days represented by value.

/// </returns>

public DateTime AddDays(double value) => AddUnits(value, MaxDays, TimeSpan.TicksPerDay);

/// <summary>

/// Returns a new <see cref="DateTime"/> that adds the specified number of hours to the value of this instance.

/// </summary>

/// <param name="value">A number of whole and fractional hours. The value parameter can be negative or positive.</param>

/// <returns>

/// An object whose value is the sum of the date and time represented by this instance and the number of hours represented by value.

/// </returns>

public DateTime AddHours(double value) => AddUnits(value, MaxHours, TimeSpan.TicksPerHour);

/// <summary>

/// Returns a new <see cref="DateTime"/> that adds the specified number of milliseconds to the value of this instance.

/// </summary>

/// <param name="value">A number of whole and fractional milliseconds. The value parameter can be negative or positive.</param>

/// <returns>

/// An object whose value is the sum of the date and time represented by this instance and the number of milliseconds represented by value.

/// </returns>

public DateTime AddMilliseconds(double value) => AddUnits(value, MaxMillis, TimeSpan.TicksPerMillisecond);

/// <summary>

/// Returns a new <see cref="DateTime"/> that adds the specified number of microseconds to the value of this instance.

/// </summary>

/// <param name="value">

/// A number of whole and fractional microseconds.

/// The <paramref name="value"/> parameter can be negative or positive.

/// Note that this value is rounded to the nearest integer.

/// </param>

/// <returns>

/// An object whose value is the sum of the date and time represented

/// by this instance and the number of microseconds represented by <paramref name="value"/>.

/// </returns>

/// <remarks>

/// This method does not change the value of this <see cref="DateTime"/>. Instead, it returns a new <see cref="DateTime"/>

/// whose value is the result of this operation.

///

/// The fractional part of value is the fractional part of a microsecond.

/// For example, 4.5 is equivalent to 4 microseconds and 50 ticks, where one microsecond = 10 ticks.

///

/// The value parameter is rounded to the nearest integer.

/// </remarks>

/// <exception cref="ArgumentOutOfRangeException">

/// The resulting <see cref="DateTime"/> is less than <see cref="MinValue"/> or greater than <see cref="MaxValue"/>.

/// </exception>

public DateTime AddMicroseconds(double value) => AddUnits(value, MaxMicroseconds, TimeSpan.TicksPerMicrosecond);

/// <summary>

/// Returns a new <see cref="DateTime"/> that adds the specified number of minutes to the value of this instance.

/// </summary>

/// <param name="value">A number of whole and fractional minutes. The value parameter can be negative or positive.</param>

/// <returns>

/// An object whose value is the sum of the date and time represented by this instance and the number of minutes represented by value.

/// </returns>

public DateTime AddMinutes(double value) => AddUnits(value, MaxMinutes, TimeSpan.TicksPerMinute);

// Returns the DateTime resulting from adding the given number of

// months to this DateTime. The result is computed by incrementing

// (or decrementing) the year and month parts of this DateTime by

// months months, and, if required, adjusting the day part of the

// resulting date downwards to the last day of the resulting month in the

// resulting year. The time-of-day part of the result is the same as the

// time-of-day part of this DateTime.

//

// In more precise terms, considering this DateTime to be of the

// form y / m / d + t, where y is the

// year, m is the month, d is the day, and t is the

// time-of-day, the result is y1 / m1 / d1 + t,

// where y1 and m1 are computed by adding months months

// to y and m, and d1 is the largest value less than

// or equal to d that denotes a valid day in month m1 of year

// y1.

//

public DateTime AddMonths(int months) => AddMonths(this, months);

private static DateTime AddMonths(DateTime date, int months)

{

if (months < -120000 || months > 120000) throw new ArgumentOutOfRangeException(nameof(months), SR.ArgumentOutOfRange_DateTimeBadMonths);

date.GetDate(out int year, out int month, out int day);

int y = year, d = day;

int m = month + months;

int q = m > 0 ? (int)((uint)(m - 1) / 12) : m / 12 - 1;

y += q;

m -= q * 12;

if (y < 1 || y > 9999) ThrowDateArithmetic(2);

ReadOnlySpan<uint> daysTo = IsLeapYear(y) ? DaysToMonth366 : DaysToMonth365;

uint daysToMonth = daysTo[m - 1];

int days = (int)(daysTo[m] - daysToMonth);

if (d > days) d = days;

uint n = DaysToYear((uint)y) + daysToMonth + (uint)d - 1;

return new DateTime(n * (ulong)TimeSpan.TicksPerDay + date.UTicks % TimeSpan.TicksPerDay | date.InternalKind);

}

/// <summary>

/// Returns a new <see cref="DateTime"/> that adds the specified number of seconds to the value of this instance.

/// </summary>

/// <param name="value">A number of whole and fractional seconds. The value parameter can be negative or positive.</param>

/// <returns>

/// An object whose value is the sum of the date and time represented by this instance and the number of seconds represented by value.

/// </returns>

public DateTime AddSeconds(double value) => AddUnits(value, MaxSeconds, TimeSpan.TicksPerSecond);

// Returns the DateTime resulting from adding the given number of

// 100-nanosecond ticks to this DateTime. The value argument

// is permitted to be negative.

//

public DateTime AddTicks(long value)

{

ulong ticks = (ulong)(Ticks + value);

if (ticks > MaxTicks) ThrowDateArithmetic(0);

return new DateTime(ticks | InternalKind);

}

// TryAddTicks is exact as AddTicks except it doesn't throw

internal bool TryAddTicks(long value, out DateTime result)