CSE2410 Fall 2014 Bounce

// Copyright 2006-2008 the V8 project authors. All rights reserved.

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

//

//     * Redistributions of source code must retain the above copyright

//       notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above

//       copyright notice, this list of conditions and the following

//       disclaimer in the documentation and/or other materials provided

//       with the distribution.

//     * Neither the name of Google Inc. nor the names of its

//       contributors may be used to endorse or promote products derived

//       from this software without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// This file relies on the fact that the following declarations have been made

// in v8natives.js:

// const $isNaN = GlobalIsNaN;

// const $isFinite = GlobalIsFinite;

// -------------------------------------------------------------------

// This file contains date support implemented in JavaScript.

// Keep reference to original values of some global properties.  This

// has the added benefit that the code in this file is isolated from

// changes to these properties.

const $Date = global.Date;

// ECMA 262 - 15.9.1.2

function Day(time) {

  return FLOOR(time/msPerDay);

}

// ECMA 262 - 5.2

function Modulo(value, remainder) {

  var mod = value % remainder;

  // Guard against returning -0.

  if (mod == 0) return 0;

  return mod >= 0 ? mod : mod + remainder;

}

function TimeWithinDay(time) {

  return Modulo(time, msPerDay);

}

// ECMA 262 - 15.9.1.3

function DaysInYear(year) {

  if (year % 4 != 0) return 365;

  if ((year % 100 == 0) && (year % 400 != 0)) return 365;

  return 366;

}

function DayFromYear(year) {

  return 365 * (year-1970)

      + FLOOR((year-1969)/4)

      - FLOOR((year-1901)/100)

      + FLOOR((year-1601)/400);

}

function TimeFromYear(year) {

  return msPerDay * DayFromYear(year);

}

function YearFromTime(time) {

  return FromJulianDay(Day(time) + kDayZeroInJulianDay).year;

}

function InLeapYear(time) {

  return DaysInYear(YearFromTime(time)) == 366 ? 1 : 0;

}

// ECMA 262 - 15.9.1.4

function MonthFromTime(time) {

  return FromJulianDay(Day(time) + kDayZeroInJulianDay).month;

}

function DayWithinYear(time) {

  return Day(time) - DayFromYear(YearFromTime(time));

}

// ECMA 262 - 15.9.1.5

function DateFromTime(time) {

  return FromJulianDay(Day(time) + kDayZeroInJulianDay).date;

}

// ECMA 262 - 15.9.1.9

function EquivalentYear(year) {

  // Returns an equivalent year in the range [2008-2035] matching

  // - leap year.

  // - week day of first day.

  var time = TimeFromYear(year);

  var recent_year = (InLeapYear(time) == 0 ? 1967 : 1956) + 

      (WeekDay(time) * 12) % 28;

  // Find the year in the range 2008..2037 that is equivalent mod 28.

  // Add 3*28 to give a positive argument to the modulus operator.

  return 2008 + (recent_year + 3*28 - 2008) % 28;

}

function EquivalentTime(t) {

  // The issue here is that some library calls don't work right for dates

  // that cannot be represented using a non-negative signed 32 bit integer

  // (measured in whole seconds based on the 1970 epoch).

  // We solve this by mapping the time to a year with same leap-year-ness

  // and same starting day for the year.  The ECMAscript specification says

  // we must do this, but for compatability with other browsers, we use

  // the actual year if it is in the range 1970..2037

  if (t >= 0 && t <= 2.1e12) return t;

  var day = MakeDay(EquivalentYear(YearFromTime(t)), MonthFromTime(t), DateFromTime(t));

  return TimeClip(MakeDate(day, TimeWithinDay(t)));

}

var daylight_cache_time = $NaN;

var daylight_cache_offset;

function DaylightSavingsOffset(t) {

  if (t == daylight_cache_time) {

    return daylight_cache_offset;

  }

  var offset = %DateDaylightSavingsOffset(EquivalentTime(t));

  daylight_cache_time = t;

  daylight_cache_offset = offset;

  return offset;

}

var timezone_cache_time = $NaN;

var timezone_cache_timezone;

function LocalTimezone(t) {

  if(t == timezone_cache_time) {

    return timezone_cache_timezone;

  }

  var timezone = %DateLocalTimezone(EquivalentTime(t));

  timezone_cache_time = t;

  timezone_cache_timezone = timezone;

  return timezone;

}

function WeekDay(time) {

  return Modulo(Day(time) + 4, 7);

}

var local_time_offset = %DateLocalTimeOffset();

function LocalTime(time) {

  if ($isNaN(time)) return time;

  return time + local_time_offset + DaylightSavingsOffset(time);

}

function LocalTimeNoCheck(time) {

  return time + local_time_offset + DaylightSavingsOffset(time);

}

function UTC(time) {

  if ($isNaN(time)) return time;

  var tmp = time - local_time_offset;

  return tmp - DaylightSavingsOffset(tmp);

}

// ECMA 262 - 15.9.1.10

function HourFromTime(time) {

  return Modulo(FLOOR(time / msPerHour), HoursPerDay);

}

function MinFromTime(time) {

  return Modulo(FLOOR(time / msPerMinute), MinutesPerHour);

}

function SecFromTime(time) {

  return Modulo(FLOOR(time / msPerSecond), SecondsPerMinute);

}

function msFromTime(time) {

  return Modulo(time, msPerSecond);

}

// ECMA 262 - 15.9.1.11

function MakeTime(hour, min, sec, ms) {

  if (!$isFinite(hour)) return $NaN;

  if (!$isFinite(min)) return $NaN;

  if (!$isFinite(sec)) return $NaN;

  if (!$isFinite(ms)) return $NaN;

  return TO_INTEGER(hour) * msPerHour

      + TO_INTEGER(min) * msPerMinute

      + TO_INTEGER(sec) * msPerSecond

      + TO_INTEGER(ms);

}

// ECMA 262 - 15.9.1.12

function TimeInYear(year) {

  return DaysInYear(year) * msPerDay;

}

// Compute modified Julian day from year, month, date.

function ToJulianDay(year, month, date) {

  var jy = (month > 1) ? year : year - 1;

  var jm = (month > 1) ? month + 2 : month + 14;

  var ja = FLOOR(jy / 100);

  return FLOOR(FLOOR(365.25*jy) + FLOOR(30.6001*jm) + date + 1720995) + 2 - ja + FLOOR(0.25*ja);

}

var four_year_cycle_table = CalculateDateTable();

function CalculateDateTable() {

  var month_lengths = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];

  var four_year_cycle_table = new $Array(1461);

  var cumulative = 0;

  var position = 0;

  var leap_position = 0;

  for (var month = 0; month < 12; month++) {

    var month_bits = month << kMonthShift;

    var length = month_lengths[month];

    for (var day = 1; day <= length; day++) {

      four_year_cycle_table[leap_position] =

        month_bits + day;

      four_year_cycle_table[366 + position] =

        (1 << kYearShift) + month_bits + day;

      four_year_cycle_table[731 + position] =

        (2 << kYearShift) + month_bits + day;

      four_year_cycle_table[1096 + position] =

        (3 << kYearShift) + month_bits + day;

      leap_position++;

      position++;

    }

    if (month == 1) {

      four_year_cycle_table[leap_position++] = month_bits + 29;

    }

  }

  return four_year_cycle_table;

}

// Constructor for creating objects holding year, month, and date.

// Introduced to ensure the two return points in FromJulianDay match same map.

function DayTriplet(year, month, date) {

  this.year = year;

  this.month = month;

  this.date = date;

}

var julian_day_cache_triplet;

var julian_day_cache_day = $NaN;

// Compute year, month, and day from modified Julian day.

// The missing days in 1582 are ignored for JavaScript compatibility.

function FromJulianDay(julian) {

  if (julian_day_cache_day == julian) {

    return julian_day_cache_triplet;

  }

  var result;

  // Avoid floating point and non-Smi maths in common case.  This is also a period of

  // time where leap years are very regular.  The range is not too large to avoid overflow

  // when doing the multiply-to-divide trick.

  if (julian > kDayZeroInJulianDay &&

      (julian - kDayZeroInJulianDay) < 40177) { // 1970 - 2080

    var jsimple = (julian - kDayZeroInJulianDay) + 731; // Day 0 is 1st January 1968

    var y = 1968;

    // Divide by 1461 by multiplying with 22967 and shifting down by 25!

    var after_1968 = (jsimple * 22967) >> 25;

    y += after_1968 << 2;

    jsimple -= 1461 * after_1968;

    var four_year_cycle = four_year_cycle_table[jsimple];

    result = new DayTriplet(y + (four_year_cycle >> kYearShift),

                            (four_year_cycle & kMonthMask) >> kMonthShift,

                            four_year_cycle & kDayMask);

  } else {

    var jalpha = FLOOR((julian - 1867216.25) / 36524.25);

    var jb = julian + 1 + jalpha - FLOOR(0.25 * jalpha) + 1524;

    var jc = FLOOR(6680.0 + ((jb-2439870) - 122.1)/365.25);

    var jd = FLOOR(365 * jc + (0.25 * jc));

    var je = FLOOR((jb - jd)/30.6001);

    var m = je - 1;

    if (m > 12) m -= 13;

    var y = jc - 4715;

    if (m > 2) { --y; --m; }

    var d = jb - jd - FLOOR(30.6001 * je);

    result = new DayTriplet(y, m, d);

  }

  julian_day_cache_day = julian;

  julian_day_cache_triplet = result;

  return result;

}

// Compute number of days given a year, month, date.

// Note that month and date can lie outside the normal range.

//   For example:

//     MakeDay(2007, -4, 20) --> MakeDay(2006, 8, 20)

//     MakeDay(2007, -33, 1) --> MakeDay(2004, 3, 1)

//     MakeDay(2007, 14, -50) --> MakeDay(2007, 8, 11)

function MakeDay(year, month, date) {

  if (!$isFinite(year) || !$isFinite(month) || !$isFinite(date)) return $NaN;

  // Conversion to integers.

  year = TO_INTEGER(year);

  month = TO_INTEGER(month);

  date = TO_INTEGER(date);

  // Overflow months into year.

  year = year + FLOOR(month/12);

  month = month % 12;

  if (month < 0) {

    month += 12;

  }

  // Return days relative to Jan 1 1970.

  return ToJulianDay(year, month, date) - kDayZeroInJulianDay;

}

// ECMA 262 - 15.9.1.13

function MakeDate(day, time) {

  if (!$isFinite(day)) return $NaN;

  if (!$isFinite(time)) return $NaN;

  return day * msPerDay + time;

}

// ECMA 262 - 15.9.1.14

function TimeClip(time) {

  if (!$isFinite(time)) return $NaN;

  if ($abs(time) > 8.64E15) return $NaN;

  return TO_INTEGER(time);

}

%SetCode($Date, function(year, month, date, hours, minutes, seconds, ms) {

  if (%IsConstructCall()) {

    // ECMA 262 - 15.9.3

    var argc = %_ArgumentsLength();

    if (argc == 0) {

      %_SetValueOf(this, %DateCurrentTime());

      return;

    }

    if (argc == 1) {

      // According to ECMA 262, no hint should be given for this

      // conversion.  However, ToPrimitive defaults to String Hint

      // for Date objects which will lose precision when the Date

      // constructor is called with another Date object as its

      // argument.  We therefore use Number Hint for the conversion

      // (which is the default for everything else than Date

      // objects).  This makes us behave like KJS and SpiderMonkey.

      var time = ToPrimitive(year, NUMBER_HINT);

      if (IS_STRING(time)) {

        %_SetValueOf(this, DateParse(time));

      } else {

        %_SetValueOf(this, TimeClip(ToNumber(time)));

      }

      return;

    }

    year = ToNumber(year);

    month = ToNumber(month);

    date = argc > 2 ? ToNumber(date) : 1;

    hours = argc > 3 ? ToNumber(hours) : 0;

    minutes = argc > 4 ? ToNumber(minutes) : 0;

    seconds = argc > 5 ? ToNumber(seconds) : 0;

    ms = argc > 6 ? ToNumber(ms) : 0;

    year = (!$isNaN(year) && 0 <= TO_INTEGER(year) && TO_INTEGER(year) <= 99)

        ? 1900 + TO_INTEGER(year) : year;

    var day = MakeDay(year, month, date);

    var time = MakeTime(hours, minutes, seconds, ms);

    %_SetValueOf(this, TimeClip(UTC(MakeDate(day, time))));

  } else {

    // ECMA 262 - 15.9.2

    return (new $Date()).toString();

  }

});

// Helper functions.

function GetTimeFrom(aDate) {

  if (IS_DATE(aDate)) return %_ValueOf(aDate);

  throw new $TypeError('this is not a Date object.');

}

function GetMillisecondsFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return msFromTime(LocalTimeNoCheck(t));

}

function GetUTCMillisecondsFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return msFromTime(t);

}

function GetSecondsFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return SecFromTime(LocalTimeNoCheck(t));

}

function GetUTCSecondsFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return SecFromTime(t);

}

function GetMinutesFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return MinFromTime(LocalTimeNoCheck(t));

}

function GetUTCMinutesFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return MinFromTime(t);

}

function GetHoursFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return HourFromTime(LocalTimeNoCheck(t));

}

function GetUTCHoursFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return HourFromTime(t);

}

function GetFullYearFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return YearFromTime(LocalTimeNoCheck(t));

}

function GetUTCFullYearFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return YearFromTime(t);

}

function GetMonthFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return MonthFromTime(LocalTimeNoCheck(t));

}

function GetUTCMonthFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return MonthFromTime(t);

}

function GetDateFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return DateFromTime(LocalTimeNoCheck(t));

}

function GetUTCDateFrom(aDate) {

  var t = GetTimeFrom(aDate);

  if ($isNaN(t)) return t;

  return DateFromTime(t);

}

%FunctionSetPrototype($Date, new $Date($NaN));

var WeekDays = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'];

var Months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];

function TwoDigitString(value) {

  return value < 10 ? "0" + value : "" + value;

}

function DateString(time) {

  var YMD = FromJulianDay(Day(time) + kDayZeroInJulianDay);

  return WeekDays[WeekDay(time)] + ' '

      + Months[YMD.month] + ' '

      + TwoDigitString(YMD.date) + ' '

      + YMD.year;

}

var LongWeekDays = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];

var LongMonths = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];

function LongDateString(time) {

  var YMD = FromJulianDay(Day(time) + kDayZeroInJulianDay);

  return LongWeekDays[WeekDay(time)] + ', '

      + LongMonths[YMD.month] + ' '

      + TwoDigitString(YMD.date) + ', '

      + YMD.year;

}

function TimeString(time) {

  return TwoDigitString(HourFromTime(time)) + ':'

      + TwoDigitString(MinFromTime(time)) + ':'

      + TwoDigitString(SecFromTime(time));

}

function LocalTimezoneString(time) {

  var timezoneOffset = (local_time_offset + DaylightSavingsOffset(time)) / msPerMinute;

  var sign = (timezoneOffset >= 0) ? 1 : -1;

  var hours = FLOOR((sign * timezoneOffset)/60);

  var min   = FLOOR((sign * timezoneOffset)%60);

  var gmt = ' GMT' + ((sign == 1) ? '+' : '-') + TwoDigitString(hours) + TwoDigitString(min);

  return gmt + ' (' +  LocalTimezone(time) + ')';

}

function DatePrintString(time) {

  return DateString(time) + ' ' + TimeString(time);

}

// -------------------------------------------------------------------

// Reused output buffer.

var parse_buffer = $Array(7);

// ECMA 262 - 15.9.4.2

function DateParse(string) {

  var arr = %DateParseString(ToString(string), parse_buffer);

  if (IS_NULL(arr)) return $NaN;

  var day = MakeDay(arr[0], arr[1], arr[2]);

  var time = MakeTime(arr[3], arr[4], arr[5], 0);

  var date = MakeDate(day, time);

  if (IS_NULL(arr[6])) {

    return TimeClip(UTC(date));

  } else {

    return TimeClip(date - arr[6] * 1000);

  }

}

// ECMA 262 - 15.9.4.3

function DateUTC(year, month, date, hours, minutes, seconds, ms) {

  year = ToNumber(year);

  month = ToNumber(month);

  var argc = %_ArgumentsLength();

  date = argc > 2 ? ToNumber(date) : 1;

  hours = argc > 3 ? ToNumber(hours) : 0;

  minutes = argc > 4 ? ToNumber(minutes) : 0;

  seconds = argc > 5 ? ToNumber(seconds) : 0;

  ms = argc > 6 ? ToNumber(ms) : 0;

  year = (!$isNaN(year) && 0 <= TO_INTEGER(year) && TO_INTEGER(year) <= 99)

      ? 1900 + TO_INTEGER(year) : year;

  var day = MakeDay(year, month, date);

  var time = MakeTime(hours, minutes, seconds, ms);

  return %_SetValueOf(this, TimeClip(MakeDate(day, time)));

}

// Mozilla-specific extension. Returns the number of milliseconds

// elapsed since 1 January 1970 00:00:00 UTC.

function DateNow() {

  return %DateCurrentTime();

}

// ECMA 262 - 15.9.5.2

function DateToString() {

  var t = GetTimeFrom(this);

  if ($isNaN(t)) return kInvalidDate;

  return DatePrintString(LocalTimeNoCheck(t)) + LocalTimezoneString(t);

}

// ECMA 262 - 15.9.5.3

function DateToDateString() {

  var t = GetTimeFrom(this);

  if ($isNaN(t)) return kInvalidDate;

  return DateString(LocalTimeNoCheck(t));

}

// ECMA 262 - 15.9.5.4

function DateToTimeString() {

  var t = GetTimeFrom(this);

  if ($isNaN(t)) return kInvalidDate;

  var lt = LocalTimeNoCheck(t);

  return TimeString(lt) + LocalTimezoneString(lt);

}

// ECMA 262 - 15.9.5.5

function DateToLocaleString() {

  return DateToString.call(this);

}

// ECMA 262 - 15.9.5.6

function DateToLocaleDateString() {

  var t = GetTimeFrom(this);

  if ($isNaN(t)) return kInvalidDate;

  return LongDateString(LocalTimeNoCheck(t));

}

// ECMA 262 - 15.9.5.7

function DateToLocaleTimeString() {

  var t = GetTimeFrom(this);

  if ($isNaN(t)) return kInvalidDate;

  var lt = LocalTimeNoCheck(t);

  return TimeString(lt);

}

// ECMA 262 - 15.9.5.8

function DateValueOf() {

  return GetTimeFrom(this);

}

// ECMA 262 - 15.9.5.9

function DateGetTime() {

  return GetTimeFrom(this);

}

// ECMA 262 - 15.9.5.10

function DateGetFullYear() {

  return GetFullYearFrom(this)

}

// ECMA 262 - 15.9.5.11

function DateGetUTCFullYear() {

  return GetUTCFullYearFrom(this)

}

// ECMA 262 - 15.9.5.12

function DateGetMonth() {

  return GetMonthFrom(this);

}

// ECMA 262 - 15.9.5.13

function DateGetUTCMonth() {

  return GetUTCMonthFrom(this);

}

// ECMA 262 - 15.9.5.14

function DateGetDate() {

  return GetDateFrom(this);

}

// ECMA 262 - 15.9.5.15

function DateGetUTCDate() {

  return GetUTCDateFrom(this);

}

// ECMA 262 - 15.9.5.16

function DateGetDay() {

  var t = GetTimeFrom(this);

  if ($isNaN(t)) return t;

  return WeekDay(LocalTimeNoCheck(t));

}

// ECMA 262 - 15.9.5.17

function DateGetUTCDay() {

  var t = GetTimeFrom(this);

  if ($isNaN(t)) return t;

  return WeekDay(t);

}

// ECMA 262 - 15.9.5.18

function DateGetHours() {

  return GetHoursFrom(this);

}

// ECMA 262 - 15.9.5.19

function DateGetUTCHours() {

  return GetUTCHoursFrom(this);

}

// ECMA 262 - 15.9.5.20

function DateGetMinutes() {

  return GetMinutesFrom(this);

}

// ECMA 262 - 15.9.5.21

function DateGetUTCMinutes() {

  return GetUTCMinutesFrom(this);

}

// ECMA 262 - 15.9.5.22

function DateGetSeconds() {

  return GetSecondsFrom(this);

}

// ECMA 262 - 15.9.5.23

function DateGetUTCSeconds() {

  return GetUTCSecondsFrom(this);

}

// ECMA 262 - 15.9.5.24

function DateGetMilliseconds() {

  return GetMillisecondsFrom(this);

}

// ECMA 262 - 15.9.5.25

function DateGetUTCMilliseconds() {

  return GetUTCMillisecondsFrom(this);

}

// ECMA 262 - 15.9.5.26

function DateGetTimezoneOffset() {

  var t = GetTimeFrom(this);

  if ($isNaN(t)) return t;

  return (t - LocalTimeNoCheck(t)) / msPerMinute;

}

// ECMA 262 - 15.9.5.27

function DateSetTime(ms) {

  if (!IS_DATE(this)) throw new $TypeError('this is not a Date object.');

  return %_SetValueOf(this, TimeClip(ToNumber(ms)));

}

// ECMA 262 - 15.9.5.28

function DateSetMilliseconds(ms) {

  var t = LocalTime(GetTimeFrom(this));

  ms = ToNumber(ms);

  var time = MakeTime(HourFromTime(t), MinFromTime(t), SecFromTime(t), ms);

  return %_SetValueOf(this, TimeClip(UTC(MakeDate(Day(t), time))));

}

// ECMA 262 - 15.9.5.29

function DateSetUTCMilliseconds(ms) {

  var t = GetTimeFrom(this);

  ms = ToNumber(ms);

  var time = MakeTime(HourFromTime(t), MinFromTime(t), SecFromTime(t), ms);

  return %_SetValueOf(this, TimeClip(MakeDate(Day(t), time)));

}

// ECMA 262 - 15.9.5.30

function DateSetSeconds(sec, ms) {

  var t = LocalTime(GetTimeFrom(this));

  sec = ToNumber(sec);

  ms = %_ArgumentsLength() < 2 ? GetMillisecondsFrom(this) : ToNumber(ms);

  var time = MakeTime(HourFromTime(t), MinFromTime(t), sec, ms);

  return %_SetValueOf(this, TimeClip(UTC(MakeDate(Day(t), time))));

}

// ECMA 262 - 15.9.5.31

function DateSetUTCSeconds(sec, ms) {

  var t = GetTimeFrom(this);

  sec = ToNumber(sec);

  ms = %_ArgumentsLength() < 2 ? GetUTCMillisecondsFrom(this) : ToNumber(ms);

  var time = MakeTime(HourFromTime(t), MinFromTime(t), sec, ms);

  return %_SetValueOf(this, TimeClip(MakeDate(Day(t), time)));

}

// ECMA 262 - 15.9.5.33

function DateSetMinutes(min, sec, ms) {

  var t = LocalTime(GetTimeFrom(this));

  min = ToNumber(min);

  var argc = %_ArgumentsLength();

  sec = argc < 2 ? GetSecondsFrom(this) : ToNumber(sec);

  ms = argc < 3 ? GetMillisecondsFrom(this) : ToNumber(ms);

  var time = MakeTime(HourFromTime(t), min, sec, ms);

  return %_SetValueOf(this, TimeClip(UTC(MakeDate(Day(t), time))));

}

// ECMA 262 - 15.9.5.34

function DateSetUTCMinutes(min, sec, ms) {

  var t = GetTimeFrom(this);

  min = ToNumber(min);

  var argc = %_ArgumentsLength();

  sec = argc < 2 ? GetUTCSecondsFrom(this) : ToNumber(sec);

  ms = argc < 3 ? GetUTCMillisecondsFrom(this) : ToNumber(ms);

  var time = MakeTime(HourFromTime(t), min, sec, ms);

  return %_SetValueOf(this, TimeClip(MakeDate(Day(t), time)));

}

// ECMA 262 - 15.9.5.35

function DateSetHours(hour, min, sec, ms) {

  var t = LocalTime(GetTimeFrom(this));

  hour = ToNumber(hour);

  var argc = %_ArgumentsLength();

  min = argc < 2 ? GetMinutesFrom(this) : ToNumber(min);

  sec = argc < 3 ? GetSecondsFrom(this) : ToNumber(sec);

  ms = argc < 4 ? GetMillisecondsFrom(this) : ToNumber(ms);

  var time = MakeTime(hour, min, sec, ms);

  return %_SetValueOf(this, TimeClip(UTC(MakeDate(Day(t), time))));

}

// ECMA 262 - 15.9.5.34

function DateSetUTCHours(hour, min, sec, ms) {

  var t = GetTimeFrom(this);

  hour = ToNumber(hour);

  var argc = %_ArgumentsLength();

  min = argc < 2 ? GetUTCMinutesFrom(this) : ToNumber(min);

  sec = argc < 3 ? GetUTCSecondsFrom(this) : ToNumber(sec);

  ms = argc < 4 ? GetUTCMillisecondsFrom(this) : ToNumber(ms);

  var time = MakeTime(hour, min, sec, ms);

  return %_SetValueOf(this, TimeClip(MakeDate(Day(t), time)));

}

// ECMA 262 - 15.9.5.36

function DateSetDate(date) {

  var t = LocalTime(GetTimeFrom(this));

  date = ToNumber(date);

  var day = MakeDay(YearFromTime(t), MonthFromTime(t), date);

  return %_SetValueOf(this, TimeClip(UTC(MakeDate(day, TimeWithinDay(t)))));

}

// ECMA 262 - 15.9.5.37

function DateSetUTCDate(date) {

  var t = GetTimeFrom(this);

  date = ToNumber(date);

  var day = MakeDay(YearFromTime(t), MonthFromTime(t), date);

  return %_SetValueOf(this, TimeClip(MakeDate(day, TimeWithinDay(t))));

}

// ECMA 262 - 15.9.5.38

function DateSetMonth(month, date) {

  var t = LocalTime(GetTimeFrom(this));

  month = ToNumber(month);

  date = %_ArgumentsLength() < 2 ? GetDateFrom(this) : ToNumber(date);

  var day = MakeDay(YearFromTime(t), month, date);

  return %_SetValueOf(this, TimeClip(UTC(MakeDate(day, TimeWithinDay(t)))));

}

// ECMA 262 - 15.9.5.39

function DateSetUTCMonth(month, date) {

  var t = GetTimeFrom(this);

  month = ToNumber(month);

  date = %_ArgumentsLength() < 2 ? GetUTCDateFrom(this) : ToNumber(date);

  var day = MakeDay(YearFromTime(t), month, date);

  return %_SetValueOf(this, TimeClip(MakeDate(day, TimeWithinDay(t))));

}

// ECMA 262 - 15.9.5.40

function DateSetFullYear(year, month, date) {

  var t = GetTimeFrom(this);

  t = $isNaN(t) ? 0 : LocalTimeNoCheck(t);

  year = ToNumber(year);

  var argc = %_ArgumentsLength();

  month = argc < 2 ? MonthFromTime(t) : ToNumber(month);

  date = argc < 3 ? DateFromTime(t) : ToNumber(date);

  var day = MakeDay(year, month, date);

  return %_SetValueOf(this, TimeClip(UTC(MakeDate(day, TimeWithinDay(t)))));

}

// ECMA 262 - 15.9.5.41

function DateSetUTCFullYear(year, month, date) {

  var t = GetTimeFrom(this);

  if ($isNaN(t)) t = 0;

  var argc = %_ArgumentsLength();

  year = ToNumber(year);

  month = argc < 2 ? MonthFromTime(t) : ToNumber(month);

  date = argc < 3 ? DateFromTime(t) : ToNumber(date);

  var day = MakeDay(year, month, date);

  return %_SetValueOf(this, TimeClip(MakeDate(day, TimeWithinDay(t))));

}

// ECMA 262 - 15.9.5.42

function DateToUTCString() {

  var t = GetTimeFrom(this);

  if ($isNaN(t)) return kInvalidDate;

  // Return UTC string of the form: Sat, 31 Jan 1970 23:00:00 GMT

  return WeekDays[WeekDay(t)] + ', '

      + TwoDigitString(DateFromTime(t)) + ' '

      + Months[MonthFromTime(t)] + ' '

      + YearFromTime(t) + ' '

      + TimeString(t) + ' GMT';

}

// ECMA 262 - B.2.4

function DateGetYear() {