How to detect the user's locale date and time format

Question

Is there a possibility to determine, with pure Javascript, what date time FORMAT has user configured on his operating system (Windows, Linux, MAC OS, etc.)?

Thanks in advance.

EDIT: I know about the method toLocaleString(), but this isn't help me to get the format that client has configured on his local machine.

Answer 1

I wrote something in pure javascript that works in IE/Firefox/Chrome. It will out put MM/DD/YYYY or DD/MM/YYYY,... depending in toLocalDateString().

Did not work on Safari but new Date().toLocalDateString() did not either.

Here is a jsFiddle

 //Create a known date string
var y = new Date(2013, 9, 25);
var lds = y.toLocaleDateString();

//search for the position of the year, day, and month
var yPosi = lds.search("2013");
var dPosi = lds.search("25");
var mPosi = lds.search("10");

//Sometimes the month is displayed by the month name so guess where it is
if(mPosi == -1)
{
    mPosi = lds.search("9");
    if(mPosi == -1)
    {
        //if the year and day are not first then maybe month is first
        if(yPosi != 0 && dPosi != 0)
        {
            mPosi = 0;
        }
        //if year and day are not last then maybe month is last
        else if((yPosi+4 <  lds.length) && (dPosi+2 < lds.length)){
            mPosi = Infinity;
        }
        //otherwist is in the middle
        else  if(yPosi < dPosi){
            mPosi = ((dPosi - yPosi)/2) + yPosi;            
        }else if(dPosi < yPosi){
            mPosi = ((yPosi - dPosi)/2) + dPosi;
        }   
    }

}


var formatString="";
var order = [yPosi, dPosi, mPosi];
order.sort(function(a,b){return a-b});

for(i=0; i < order.length; i++)
{
    if(order[i] == yPosi)
    {
        formatString += "YYYY/";
    }else if(order[i] == dPosi){
        formatString += "DD/";
    }else if(order[i] == mPosi){
        formatString += "MM/";
    }
}

formatString = formatString.substring(0, formatString.length-1);

$('#timeformat').html(formatString+" "+lds);

Answer 2

Here's an idea, that may or may not work.

Create a date where all the elements are distinct, like February 18th 1999 at 13:45, use toLocaleString(), then identify the elements based on their distinct values.

Could be kind of complicated and I don't have any code that might help with it, but it's an idea to be thrown out there, maybe you can make use of it.

---

EDIT: Here's some code:

var d = new Date(1999,1,18,13,45,0).toLocaleString();
document.write("<p>String: "+d+"</p>");
var f = d
    .replace(/1999/,"%Y")
    .replace(/99/,"%y")
    .replace(/F[^ ]{3,}/i,"%M")
    .replace(/F[^ ]+/i,"%m")
    .replace(/PM/,"%A")
    .replace(/pm/,"%a")
    .replace(/18[^ ]+/,"%d%S") // day number with suffix
    .replace(/18/,"%d")
    .replace(/13/,"%H")
    .replace(/1/,"%h")
    .replace(/45/,"%i")
    .replace(/00/,"%s");
    // optionally add something to detect the day of the week (Thursday, here)
document.write("<p>Format: "+f+"</p>");

Output:

String: 18 February 1999 13:45:00
Format: %d %M %Y %H:%i:%s