Get system date format using Angular js

Question

i want to get system date format using Angular js. User may have selected it as dd/mm/YYYY, dd/mm/yy ... and so on it can be any date format which is selected by user on his/her computer. Is it possible to get the date format?

--EDIT--

I don't have the value of date like 10/12/2016, 10-Dec-2016... and so on this date value also i need to pick from user's system with same format as user have selected.

Answer 1

I think that you can't find out his/her computer date format with only Javascript. If you are using some dynamic language on backend, you should try to retrieve time format that way.

Answer 2

I think you can check Mozilla MDN, but I believe JS can't get you this info, because JS is dependent on browser API. So, if a browser API provides that then it's fine otherwise use any framework like .Net or Java etc.

Answer 3

Not a full-proof solution but can but use as a reference and you can add support for new formats.

Logic

• Create a date object for a specific date that will exist for every year. Like: 31/12/2016
• Now search first non alphanumeric character. This is your delimiter.
• Now that you have 3 parts, you can find dd easily by comparing value to 31.
• Even year part is easy, since it can have 2 values, 16 or 2016.
• Month can be tricky. It can have 12 or Dec or December. For that you can have 2 checks. If number and equal to 12, it mm. If not number and length is 3, its mmm else mmmm

Now you can create var d = new Date('2016/12/31') and pass d.toLocaleDateString() to below function.

function getDateFormat(dateStr) {
  var delimiter = dateStr.match(/[^0-9a-z]/i)[0];
  var dateParts = dateStr.split(delimiter);
  var r = dateParts.map(function(d, i) {
    if (d == 31) {
      return "dd"
    } else if (!isNaN(d) && (d == 2016 || (d + 2000) == 2016)) {
      return d.toString().length === 4 ? "YYYY" : "yy"
    } else if (d == 12) {
      return "mm"
    } else if (isNaN(d)) {
      var _t = d.replace(/[^a-z]/gi, '')
      return _t.length === 3 ? "mmm" : "mmmm"
    }
  });
  return r.join(delimiter);
}

Date.prototype.getSystemDateFormat = function(){
  return getDateFormat(new Date('2016/12/31').toLocaleDateString());
}
//or
Date.prototype.SYSTEM_FORMAT = (function(){
  return getDateFormat(new Date('2016/12/31').toLocaleDateString());
})()

console.log(new Date().getSystemDateFormat())
console.log(new Date().SYSTEM_FORMAT)

var d1 = "12/31/2016"
console.log(getDateFormat(d1))

d1 = "31/12/2016"
console.log(getDateFormat(d1))

d1 = "31 December 2016"
console.log(getDateFormat(d1))

d1 = "31 Dec. 2016"
console.log(getDateFormat(d1))

d1 = "31-12-2016"
console.log(getDateFormat(d1))

d1 = "31.12.2016"
console.log(getDateFormat(d1))

You can also add functions to date.prototype to get value directly instead of calling it every time,

Date.prototype.getSystemDateFormat = function(){
  return getDateFormat(new Date('2016/12/31').toLocaleDateString());
}
//or
Date.prototype.SYSTEM_FORMAT = (function(){
  return getDateFormat(new Date('2016/12/31').toLocaleDateString());
})()

Edit 1

As correctly pointed out by @RobG, date.toLocaleString or date.toLocaleDateString are not uniform across all browsers. They are not supported by < IE11. So this is not a reliable answer. You can use it for reference though.