Safari JS cannot parse YYYY-MM-DD date format?

Question

In a project I am working on, I need to validate a date entered into an <input type="date">

With Safari 4/5 (on Mac OSX) the Javascript fails to parse dates of the format YYYY-MM-DD, returning NaN instead of the expected epoch timestamp.

I am using the following technique to validate the field just before the form is submitted:

//value = '2010-06-21'
var stamp = Date.parse(value);
if (isNaN(stamp)) {
    //notify user
} else {
    value = new Date(stamp).format_mysql();
}

Where format_mysql() is a prototype function that formats the date (correctly) into MySQL Date-Time format (YYYY-MM-DD).

Replacing the -'s with /'s (YYYY/MM/DD) yields a "correct" timestamp.

I should note that the field should accept any date format, not just YYYY-MM-DD, and that though I would like to, I cannot use libraries like Date.js

How can I fix this, or is there a better way to parse/validate a date?

Answer 1

The behavior of the Date.parse method is implementation dependent, on ECMAScript 5, this method can parse ISO8601 formatted dates, but I would recommend you to make the parsing manually.

Some time ago I've made a simple function, that can handle a format specifier argument:

function parseDate(input, format) {
  format = format || 'yyyy-mm-dd'; // default format
  var parts = input.match(/(\d+)/g), 
      i = 0, fmt = {};
  // extract date-part indexes from the format
  format.replace(/(yyyy|dd|mm)/g, function(part) { fmt[part] = i++; });

  return new Date(parts[fmt['yyyy']], parts[fmt['mm']]-1, parts[fmt['dd']]);
}

parseDate('06.21.2010', 'mm.dd.yyyy');
parseDate('21.06.2010', 'dd.mm.yyyy');
parseDate('2010/06/21', 'yyyy/mm/dd');
parseDate('2010-06-21');

Also you could detect the ECMAScript 5 behavior to parse ISO formatted dates, you can check if the Date.prototype.toISOString is available, e.g.:

if (typeof Date.prototype.toISOString == "function") {
  // ES5 ISO date parsing available
}

Answer 2

the field should accept any date format

You don't mean what you think you mean.

• It's difficult to reliably distinguish between M/D/Y (US) and D/M/Y (UK). D.M.Y is more common in the UK, but by no means universal.
• Good luck with dates before around 1600 — the Gregorian (solar) calendar was introduced in 1582, and was only (mostly universally) adopted in the 20th century (Wikipedia gives 1929). February 30 was a valid date Sweden.
• OS X gives you a choice of 13 (!) calendars, though the default is Gregorian.

Instead, I recommend using a calendar widget. I think JQuery has one, but ICBW.

Answer 3

You can get an unambiguous date from input, but you still need to check it, so a user doesn't give you April 31.

<fieldset id= "localdate"> 
<select id= "monthselect" size= "1"> 
<option selected= "selected"> January</option> 
<option> February</option> 
<option> March</option> 
<option> April</option> 
<option> May</option> 
<option> June</option> 
<option> July</option> 
<option> August</option> 
<option> September</option> 
<option> October</option> 
<option> November</option> 
<option> December</option> 
</select> 
<label> Date: <input name= "inputdate" size= "2" value= "1"> </label> 
<label> Year: <input name= "inputyear" size= "4" value= "2010"> </label> 
</fieldset> 

shortcut for document.getElementsByName

function byName(s, n){ n= n || 0; return document.getElementsByName(s)[n]; }

function getDateInput(){
    var day, y= parseInt(byName('inputyear').value),
    m= byName('monthselect').selectedIndex,
    d= parseInt(byName('inputdate').value);

    if(!y || y<1000 || y> 3000) throw 'Bad Year '+y;
    if((!d || d<1 || d> 32) throw 'Bad Date '+d;
    day= new Date(y,m,d);
    if(day.getDate()!= d) throw 'Bad Date '+d;
    value= day.format_mysql();
}

you can preset the fields to reflect the current date onload

onload= function(){
    var now= new Date();
    byName('inputyear').value= now.getFullYear();
    byName('monthselect').selectedIndex= now.getMonth();
    byName('inputdate').value= now.getDate();
}