I'm having trouble properly formatting 2-digit dates as 4-digit dates.

I have a text input field:

<input type="text" value="" class="date"/>

And then I want to format it in the "mm/dd/yyyy" format after the user enters a date. So I have an onChange event:

$('.date').on('change',function(){
    var date = new Date($(this).val());
    $(this).val((date.getMonth()+1)+'/'+date.getDate()+'/'+date.getFullYear());
});

Okay, so now es the oddities (I'll be using 12/12/12 as an example date):

1) getFullYear() returns 1912 in all IE, FF. Chrome returns 2012.

2) getYear() returns 112 in IE, Chrome. FF returns 12.

So it seems like the only option at this point is to sniff the user agent, and use that accordingly. Is there anyway around sniffing the UA?

I'm having trouble properly formatting 2-digit dates as 4-digit dates.

I have a text input field:

<input type="text" value="" class="date"/>

And then I want to format it in the "mm/dd/yyyy" format after the user enters a date. So I have an onChange event:

$('.date').on('change',function(){
    var date = new Date($(this).val());
    $(this).val((date.getMonth()+1)+'/'+date.getDate()+'/'+date.getFullYear());
});

Okay, so now es the oddities (I'll be using 12/12/12 as an example date):

1) getFullYear() returns 1912 in all IE, FF. Chrome returns 2012.

2) getYear() returns 112 in IE, Chrome. FF returns 12.

So it seems like the only option at this point is to sniff the user agent, and use that accordingly. Is there anyway around sniffing the UA?

• javascript
• jquery

• You might want to look at this post stackoverflow./questions/2997785/… - JavaScript isn't great for dates. – Brian Hoover Commented Jan 31, 2013 at 16:34
• 2 If I type in something like '04/19/10' in the Date field, how do you know whether I'm talking about 1910 or 2010? – kinsho Commented Jan 31, 2013 at 16:35
• 3 Your input should require full year. – Francis P Commented Jan 31, 2013 at 16:36
• @BrianHoover Yeah, among other things, but I the client wants JS validation/correction on the date :-S – Joel Kinzel Commented Jan 31, 2013 at 18:26
• @kinsho for this application we are assuming it is 20XX because the data we are collecting should have only happened in 20XX. – Joel Kinzel Commented Jan 31, 2013 at 18:27

3 Answers 3

Using moment.js:

const moment = require("moment")
const date = moment("21", "YY")
const year = date.format("YYYY")

you can try,first, to seperate the parts of the input

...
var input=$(this).val();
var month=input.substr(0,2)-1;
var day=input.substr(3,2);
var year=parseInt("20"+ input.substr(6,2));

and then initate a new Date object:

var date= new Date(year,month,day);

or write it back to the field, as you did:

$(this).val((date.getMonth()+1)+'/'+date.getDate()+'/'+date.getFullYear());

After asking around, I ended up using Moment.js. I tried date.js but because I'm partially working with unix timestamps, moment seemed to handle these better (IMO).