CODEWITHSUNDEEP
javascript
David Hope
David Hope

Reputation: 1536

Javascript: Convert timestamp to human readable date?

I'm simply trying to convert a timestamp back into a human readable date but what I get when converted is strange and wrong.

This is how I save the timestamp:

var timestamp = Number(new Date());
localStorag.setItem("mytimestamp", timestamp);

and this is how I get it back and convert it to readable date:

var mydate = localStorag.getItem("mytimestamp");
var jsDate = new Date(mydate*1000);

alert(jsDate);

The jsDate is wrong and I don't understand what's causing it!

Could someone please advise on this?

Upvotes: 13

Views: 50394

Answers (8)

Aurobindo Bhuyan
Aurobindo Bhuyan

Reputation: 478

if your date is string and looks like this "2023-11-08T08:49:35.000000Z". You don't need any library for formatting it.

const date = new Date("2023-11-08T08:49:35.000000Z").toDateString();
console.log(date); // "Wed Nov 08 2023"

Upvotes: 1

Riccardo Volpe
Riccardo Volpe

Reputation: 1623

JS Code

var timestamp = Number(new Date());
localStorage.setItem("mytimestamp", timestamp);
var mydate = localStorage.getItem("mytimestamp");
var jsDate = new Date(Number(mydate));
alert(jsDate);

const months = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];

const days = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];

var year = jsDate.getFullYear(),
    monthnum = jsDate.getMonth() + 1,
    twodigitsmonthnum = ("0" + monthnum).slice(-2),
    monthname = months[jsDate.getMonth()],
    daymonthnum = jsDate.getDate(),
    twodigitsdaymonthnum = ("0" + daymonthnum).slice(-2),
    dayname = days[jsDate.getDay()],
    hours = jsDate.getHours(),
    twodigitshours = ("0" + hours).slice(-2),
    minutes = jsDate.getMinutes(),
    twodigitsminutes = ("0" + minutes).slice(-2),
    seconds = jsDate.getSeconds(),
    twodigitsseconds = ("0" + seconds).slice(-2),
    milliseconds = jsDate.getMilliseconds();

alert(dayname + ", " + daymonthnum + " " + monthname + " " + year + ", " + twodigitshours + ":" + twodigitsminutes + ":" + twodigitsseconds + "." + milliseconds);

Upvotes: -1

Constantine Kobylinskyi
Constantine Kobylinskyi

Reputation: 181

Here is an easy solution using the toDateString() method:

const date = new Date(timestamp).toDateString();
console.log(date);

This will return something like: Thu Jul 14 2016

Upvotes: 18

Natsathorn
Natsathorn

Reputation: 1528

You can use the Number data type instead of date * 1000 to achieve this. See code example below:

// generate a timestamp
var timestamp = Number(new Date()) //1479895361931

Then

// get the date representation from the timestamp
var date = new Date(timestamp) // Wed Nov 23 2016 18:03:25 GMT+0800 (WITA)

Upvotes: 19

omer727
omer727

Reputation: 7565

Try using moment.js. It add functions such as 

moment().format('MMMM Do YYYY, h:mm:ss a'); // November 23rd 2016, 12:03:36 pm
moment().format('dddd');                    // Wednesday
moment().format("MMM Do YY");               // Nov 23rd 16
moment().format('YYYY [escaped] YYYY');     // 2016 escaped 2016
moment().format();                          // 2016-11-23T12:03:36+02:00

Upvotes: 4

Lix
Lix

Reputation: 47956

The cause of the issue here is when you multiply the timestamp by 1000.

If you simply pass myDate to the Date constructor you should get the correct time - 

var timestamp = Number(new Date());
localStorage.setItem("mytimestamp", timestamp);
// ...
var mydateStr = localStorage.getItem("mytimestamp");
var myDate = Number(mydateStr); // convert the string back to a number
var jsDate = new Date(mydate);

It's true that Javascript deals with milliseconds but since you are generating the timestamp with Javascript and then reading it back also with Javascript, no conversion is needed - you can use the value as-is.

As was pointed out to me by @manish in the comments, the value stored in localStorage will be a string - remember to convert it back to a number before passing it to the Date constructor.

Upvotes: 5

Tanveer
Tanveer

Reputation: 97

var yourTimestamp = localStorag.getItem("mytimestamp");
jsDate = new Date(yourTimestamp);

jsDateValues = [
   jsDate.getFullYear(),
   jsDate.getMonth()+1,
   jsDate.getDate(),
   jsDate.getHours(),
   jsDate.getMinutes(),
   jsDate.getSeconds(),
];
alert(jsDateValues); //=> [2011, 3, 25, 23, 0, 0]

and you can use the baove values and print in which format you wnat e.g dd/mm/yyyy

Upvotes: 2

Manish
Manish

Reputation: 5056

The problem here is that when you store something in localstorage its being stored as string '1479895747557' and not a number So when you get the timestamp back from localstorage its not a number its a string. Though when you multiply it the value actually changes due to internal conversion it becomes 1479895747557000 and this represents a different date from the one you saved. So the solution would be to convert the string back to a number. Here is the code that works fine. 

var timestamp = Number(new Date());
localStorage.setItem("mytimestamp", timestamp);
var mydate = localStorage.getItem("mytimestamp");
var jsDate = new Date(Number(mydate));
alert(jsDate);

Here is the code that does not performs the conversion back to number this will give you an Invalid Date. 

var timestamp = Number(new Date());
localStorage.setItem("mytimestamp", timestamp);

var mydate = localStorage.getItem("mytimestamp");

var jsDate = new Date(mydate);

alert(jsDate);

FIDDLE

Upvotes: 1

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