Create Date object by call the constructor : Date constructors « Date « JavaScript Tutorial

Constructors:

var variable = new Date();
    var variable = new Date(milliseconds1);
    var variable = new Date(string)
    var variable = new Date(year, month, day, hours, minutes, seconds, milliseconds2)

milliseconds1	The desired date is calculated from the number of milliseconds between midnight January 1, 1970 GMT and the desired date.
string	The desired date is calculated from the string representation. The format of the string should match the parse() method of the Date object.
year	A four digit representation of the year.
month	The month represented as an integer, where 0 represents January and 11 represents December.
day	The day of the month represented as an integer from 1 to 31. Optional argument.
hours	The hour represented as an integer where 0 represents 12 am (midnight) and 23 represents 11 pm. Optional argument.
minutes	The minutes in the hour represented as an integer from 0 to 59. Optional argument.
seconds	The seconds in the minute represented as an integer from 0 to 59. Optional argument.
milliseconds2	The milliseconds in the second represented as an integer from 0 to 999. Optional argument.

If arguments are provided when creating the Date object, the new object will contain the date specified. Otherwise the object will be set to the current date.

A Date object can also be created by calling Date as a function by excluding the new operator.

<html>
<head>
<script language="JavaScript" type = "text/javascript">
<!--
current_date = new Date();
document.write(current_date);
//-->
</script>
</head>
<body>
</body>
</html>

12.2.Date constructors
	12.2.1.	Create Date object by call the constructor
	12.2.2.	Create Date objects using various arguments in the Date() constructor