JavaScript tutorial:
parse method

 

Applies to: Date Object

Parses a string containing a date, and returns the number of milliseconds between that date and midnight, January 1, 1970.

Syntax

Date.parse(dateVal)

The dateVal argument is either a string containing a date in a format such as "Jan 5, 1996 08:47:00" or a VT_DATE value retrieved from an ActiveX object or other object.

Return

Returns the number of milliseconds between string date given and minight, January 1, 1970.

Example

The parse method returns an integer value representing the number of milliseconds between midnight, January 1, 1970 and the date supplied in dateVal.

The parse method is a static method of the Date object. Because it is a static method, it is invoked as shown in the following example rather than invoked as a method of a created Date object.

datestring = "February 24, 2005 10:15 AM";
alert(Date.parse(datestring) + " milliseconds");

  To run the code above, paste it into JavaScript Editor, and click the Execute button

The following rules govern what the parse method can successfully parse:

  • Short dates can use either a "/" or "-" date separator, but must follow the month/day/year format, for example "7/20/96".

  • Long dates of the form "July 10 1995" can be given with the year, month, and day in any order, and the year in 2-digit or 4-digit form. If you use the 2-digit form, the year must be greater than or equal to 70.

  • Any text inside parentheses is treated as a comment. These parentheses may be nested.

  • Both commas and spaces are treated as delimiters. Multiple delimiters are permitted.

  • Month and day names must have two or more characters. Two character names that are not unique are resolved as the last match. For example, "Ju" is resolved as July, not June.

  • The stated day of the week is ignored if it is incorrect given the remainder of the supplied date. For example, "Tuesday November 9 1996" is accepted and parsed even though that date actually falls on a Friday. The resulting Date object contains "Friday November 9 1996".

  • JavaScript handles all standard time zones, as well as Universal Coordinated Time (UTC) and Greenwich Mean Time (GMT).

  • Hours, minutes, and seconds are separated by colons, although all need not be specified. "10:", "10:11", and "10:11:12" are all valid.

  • If the 24-hour clock is used, it is an error to specify "PM" for times later than 12 noon. For example, "23:15 PM" is an error.

  • A string containing an invalid date is an error. For example, a string containing two years or two months is an error.

The following example illustrates the use of the parse method:

datestring = "February 24, 2005 2:08 PM";
function GetTime(testdate)
{
    var d, s, t;
    var MinMilli = 1000 * 60;
    var HrMilli = MinMilli * 60;
    var DyMilli = HrMilli * 24;
    d = new Date();
    t = Date.parse(testdate);
    s = "There are "
    s += Math.round(Math.abs(t / DyMilli)) + " days "
    s += "between " + testdate + " and 1/1/70";
    return(s);
}

alert(GetTime(datestring));

  To run the code above, paste it into JavaScript Editor, and click the Execute button

See also: Date Object Methods