assign javascript date to html5 datetime-local input

Question

DOM:

<input id="myTextbox" type="datetime-local" />

Javascript (jQuery):

$('#myTextbox').val(new Date().toISOString());

Doesn't work. The format of input[type=datetime-local] is supposed to be ISO 8601, which is what javascript's Date.toISOString() returns.

Answer 1

http://www.w3schools.com/jsref/jsref_toisostring.asp:

The toISOString() method converts a Date object into a string, using the ISO standard.

The standard is called ISO-8601 and the format is: YYYY-MM-DDTHH:mm:ss.sssZ

While ISO 8601 has some flexibility, the format of javascript's Date's toISOString() is exactly as shown above.

The 'Z' at the end means this is a UTC date. So, this representation includes timezone information. (Javascript dates are naturally in UTC time since they are internally represented as milliseconds since epoch.)

The format of HTML5 input with type=datetime-local must be ...

The following parts, in exactly the following order:

• A date.
• The literal string "T".
• A time.

Example:

1985-04-12T23:20:50.52

1996-12-19T16:39:57

http://www.w3.org/TR/html-markup/input.datetime-local.html

This is still ISO 8601, but stricter, and it does not allow a timezone to be specified.

Luckily, removing the timezone is as easy as removing the trailing 'Z'.

var isoStr = new Date().toISOString();
$('#myTextbox').val(isoStr.substring(0,isoStr.length-1));