date.toLocaleDateString is not a function

Question

Have simple function which returns an error:

ERROR: date.toLocaleDateString is not a function

TypeError: date.toLocaleDateString is not a function
    at FormatTime (../Src/rootdialog.js:87:58)

Function definition:

function FormatTime(time, prefix = "") {
    var date = Date.parse(time);
    return ((typeof time != "undefined") ? prefix + date.toLocaleDateString()  : "");
}

Function receives Date object as input however even explicit conversion to Date with Date.parse() does not help. Using Node.js 8.x. Any solution?

P.S. Issue was caused by BotBuilder architecture.

`Date.parse` returns a number. You are looking for `new Date`. Or, if `time` already is a Date instance, just use `time.toLocaleDateString()`! — Bergi, Aug 17 '17 at 00:43
@Bergi thanks, this works. Strange when values was inside function - their was `Date` type with `Date()` constructor, outside - become strings: probably bot framework on waterfall flow functions assignment loses type and need to convert explicitly. You may move Your comment to answers. Thanks! — Aleksey Kontsevich, Aug 17 '17 at 00:57

score 40 · Answer 1 · answered Aug 17 '20 at 06:37

40

You can use

new Date(date).toLocaleDateString();

answered Aug 17 '20 at 06:37

Viplav Soni

1,489
13
18

score 39 · Accepted Answer · answered Aug 17 '17 at 01:01

Date.parse returns a number. You are looking for new Date. Or, if time already is a Date instance, just use time.toLocaleDateString() (and make sure it really is in every call to the function)!

function formatTime(time, prefix = "") {
    return typeof time == "object" ? prefix + time.toLocaleDateString() : "";
}

score 4 · Answer 3 · answered Apr 21 '21 at 12:43

4

Got this error in a React app, solved it like this:

{ (item.created instanceof Date) ? item.created.toLocaleDateString() : new Date(item.created).toLocaleDateString() }

answered Apr 21 '21 at 12:43

Ogglas

62,132
37
328
418

You can directly use `new Date(date).toLocaleDateString();`, On your code a if condition will take time to excecute. – Viplav Soni May 06 '21 at 11:41

score 0 · Answer 4 · answered Aug 17 '17 at 01:01

You're most likely getting NaN as the result of your Date.parse(time) call. Check the MDN article on Date.parse for the types of input strings it accepts if you think your time argument should be valid.

You may want to modify your return statement so it's checking for failed parses instead of just undefined, e.g.:

function FormatTime(time, prefix = "") {
    var date = Date.parse(time); // returns NaN if it can't parse
    return Number.isNaN(date) ? "" : prefix + date.toLocaleDateString();
}

score -4 · Answer 5 · answered Aug 22 '17 at 12:45

-4

 function(ng-model_Name,ng-model_Name) {
     var fromdate = new Date($scope.ng-model_Name.from.toLocaleDateString());
     var todate = new Date($scope.ng-model_Name.to.toLocaleDateString());
     return $scope.variable= asign; 
 }

answered Aug 22 '17 at 12:45

RaVi R Pant

1

7

Please elaborate *how* and *why* this solves the issue. – Paul Kertscher Aug 22 '17 at 13:04

date.toLocaleDateString is not a function

5 Answers5