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#### Date

Instances of the `Date` class are used to store and manipulate dates and times.

A variety of get functions are provided to obtain the date, time or relevant parts, for example, `getDay()`, `getYear()`, `getHours()`, `getMilliseconds()`, `getMinutes()`, `getMonth()`, `getSeconds()`, `getTime()`.

A complementary set of functions are also provided, including `setYear()`, `setHours()`, `setMilliseconds()`, `setMinutes()`, `setMonth()`, `setSeconds()`, `setTime()`.

The functions operate using local time.

Conversion between Date objects to and from strings are provided by `parse()` and `Date::toString()`.

Elapsed time (in milliseconds) can be obtained by creating two dates, casting them to `Number` and subtracting one value from the other.

    var date1 = new Date();
    // time flies..
    var date2 = new Date();
    var timedifference = date2.getTime() - date1.getTime();

##### Static Date Functions

- parse( dateString : String ) : Number;

          var d = new Date( Date.parse( "1976-01-25T22:30:00" ) );
          d = Date.parse( "1976-01-25T22:30:00" );

  This is a static function that parses a string, `dateString`, which represents a particular date and time. It returns the number of milliseconds since midnight on the 1st January 1970. The string must be in the ISO 8601 extended format: `YYYY-MM-DD` or with time `YYYY-MM-DDTHH:MM:SS`.

##### Date Construction

    Date()
    Date( milliseconds )
    Date( year, month, day, optHour, optMinutes, optSeconds, optMilliseconds )

        var today = new Date();
        var d = new Date( 1234567 );
        var date = new Date( 1994, 4, 21 );
        var moment = new Date( 1968, 5, 11, 23, 55, 30 );

Dates can be constructed with no arguments, in which case the value is the date and time at the moment of construction using local time. A single integer argument is taken as the number of milliseconds since midnight on the 1st January 1970.

##### Date Functions

- getDate() : Number;

          var d = new Date( 1975, 12, 25 );
          var x = d.getDate();  // x == 25

  Returns the day of the month using local time. The value is always in the range 1..31.

- getDay() : Number;

          var d = new Date( 1975, 12, 25, 22, 30, 15 );
          var x = d.getDay();  // x == 4

  Returns the day of the week using local time. The value is always in the range 1..7, with the week considered to begin on Monday.

  Example:

          var IndexToDay = [ "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" ];
          var d = new Date( 1975, 12, 28 );
          System.println( IndexToDay[ d.getDay() - 1 ] ); // Prints "Sun"

- getYear() : Number;

          var d = new Date( 1975, 12, 25 );
          var x = d.getYear();  // x == 1975

  Returns the year using local time.

- getHours() : Number;

          var d = new Date( 1975, 12, 25, 22 );
          var x = d.getHours();  // x == 22

  Returns the hour using local time. The value is always in the range 0..23.

- getMilliseconds() : Number;

          var d = new Date( 1975, 12, 25, 22 );
          var x = d.getMilliseconds();  // x == 0

  Returns the milliseconds component of the date using local time. The value is always in the range 0..999. In the example, `x` is 0, because no milliseconds were specified, and the default for unspecified components of the time is 0.

- getMinutes() : Number;

          var d = new Date( 1975, 12, 25, 22, 30 );
          var x = d.getMinutes();  // x == 30

  Returns the minutes component of the date using local time. The value is always in the range 0..59.

- getMonth() : Number;

          var d = new Date( 1975, 12, 25, 22, 30 );
          var x = d.getMonth();  // x == 12

  Returns the months component of the date using local time. The value is always in the range 1..12.

  Example:

          var IndexToMonth = [ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
                               "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" ];
          var d = new Date( 1975, 12, 25 );
          System.println( IndexToMonth[ d.getMonth() - 1] ); // Prints "Dec"

- getSeconds() : Number;

          var d = new Date( 1975, 12, 25, 22, 30 );
          var x = d.getSeconds();  // x == 0

  Returns the seconds component of the date using local time. The value is always in the range 0..59. In the example `x` is 0 because no seconds were specified, and the default for unspecified components of the time is 0.

- getTime() : Number;

          var d = new Date( 1975, 12, 25, 22, 30 );
          var x = d.getTime();  // x == 1.91457e+11

  Returns the number of milliseconds since midnight on the 1st January 1970 using local time.

- setDate( dayOfTheMonth : Number );

          var d = new Date( 1975, 12, 25, 22, 30 );
          d.setDate( 30 );  // d == 1975-12-30T22:30:00

  Sets the day of the month to the specified `dayOfTheMonth` in local time.

- setYear( year : Number );

          var d = new Date( 1975, 12, 25, 22, 30 );
          d.setYear( 1980 );         // d == 1980-12-30T22:30:00

  Sets the year to the specified `year` in local time.

- setHours( hour : Number );

          var d = new Date( 1975, 12, 25, 22, 30 );
          d.setHours( 10 );  // d == 1980-12-30T10:30:00

  Sets the `hour` to the specified hour, which must be in the range 0..23, in local time. The minutes, seconds and milliseconds past the hour (`optMinutes`, `optSeconds` and `optMilliseconds`) can also be specified.

- setMilliseconds( milliseconds : Number );

          var d = new Date( 1975, 12, 25, 22, 30 );
          d.setMilliseconds( 998 );  // d == 1980-12-30T10:30:00:998

  Sets the `milliseconds` component of the date to the specified value in local time.

- setMinutes( minutes : Number );

          var d = new Date( 1975, 12, 25, 22, 30 );
          d.setMinutes( 15 );  // d == 1980-12-30T10:15:00

  Sets the `minutes` to the specified minutes, which must be in the range 0..59, in local time. The seconds and milliseconds past the minute (`optSeconds` and `optMilliseconds`) can also be specified.

- setMonth( month : Number );

          var d = new Date( 1975, 12, 25, 22, 30 );
          d.setMonth( 0 );  // d == 1980-01-11T22:30:00

  Sets the `month` to the specified month, which must be in the range 0..11, in local time.

- setSeconds()

  `setSeconds( seconds )`

          var d = new Date( 1975, 12, 25, 22, 30 );
          d.setSeconds( 25 );  // d == 1980-12-30T22:30:25

  Sets the `seconds` to the specified seconds, which must be in the range 0..59, in local time.

- setTime( milliseconds : Number );

          var d = new Date( 1975, 12, 25, 22, 30 );
          var duplicate = new Date();
          duplicate.setTime( d.getTime() );

  Sets the date and time to the local date and time given in terms of `milliseconds` since midnight on the 1st January 1970.

- toString() : String;

          var d = new Date( 1975, 12, 25, 22, 30 );
          var s = d.toString(); // s == "1975-12-25T22:30:00"

  Converts the date into a string on the ISO 8601 extended format: `YYYY-MM-DDTHH:MM:SS`.

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