Java date format to JavaScript date format - javascript

I would like to be able to convert a Java date format string, e.g. dd/MM/yyyy (07/06/2009) to a JavaScript date format string, e.g. dd/mm/yy (07/06/2009).
Has anyone done this before, or got any idea where I might find some code that already does this?
Edit:
Thanks for all the replies but now I realize my mistake and possibly why so many of you were struggling to understand the question; JavaScript doesn't have a built in date formatting ability. I am using the jQuery UI datepicker and I have been setting its date format, assuming it would be calling a standard JS function at some point, not using its own library! When I googled for formatting strings I jumped straight to the tables of what letters could be used, skipping the bit at the beginning explaining how to use the script.
Anyway I'll have to go ahead and possibly write my own I guess, converting a Java date format string into a jQuery date format string (or as close as possible) - I am working on the i18n of our product and have created a java class that stores the preferred date format string used throughout the application, my intention was to also have the ability to supply any jsps with the format string that is equivalent in JS.
Thanks anyway.

If you just need to pass a date from Java to JavaScript, the best way to do it, I think, would be to convert the Java date to milliseconds using date.getTime(), create a JavaScript date initialized with this milliseconds value with new Date(milliseconds)and then format the date with the means of the JavaScript Date object, like: date.toLocaleString().

You could use my plugin jquery-dateFormat.
// Text
$.format.date("2009-12-18 10:54:50.546", "dd/MM/yyyy");
// HTML Object
$.format.date($("#spanDate").text(), "dd/MM/yyyy");
// Scriptlet
$.format.date("<%=java.util.Date().toString()%>", "dd/MM/yyyy");
// JSON
var obj = ajaxRequest();
$.format.date(obj.date, "dd/MM/yyyy");

A similar topic has been answered here:
Converting dates in JavaScript
I personally have found this to be a rather large pain and took the author's suggestion and used a library. As noted, jQuery datepicker has one that is a viable solution if you can afford the overhead of download for your application or already using it.

Check out moment.js! It's "A lightweight javascript date library for parsing, manipulating, and formatting dates". It is a really powerful little library.
Here's an example...
var today = moment(new Date());
today.format("MMMM D, YYYY h:m A"); // outputs "April 11, 2012 2:32 PM"
// in one line...
moment().format("MMMM D, YYYY h:m A"); // outputs "April 11, 2012 2:32 PM"
Here's another example...
var a = moment([2012, 2, 12, 15, 25, 50, 125]);
a.format("dddd, MMMM Do YYYY, h:mm:ss a"); // "Monday, March 12th 2012, 3:25:50 pm"
a.format("ddd, hA"); // "Mon, 3PM"
a.format("D/M/YYYY"); // "12/3/2012"
Also, its worth mentioning to checkout date.js. I think the two libraries complement each other.

This JavaScript library should be able to help you.
http://plugins.jquery.com/project/fIsForFormat
(I don't know why they have it as a jQuery Plugin, because it works standalone.)
You'd simply split the original formatted date into its individual elements and then create a new Date Object with those elements. Then, use this library's "Date.f()" method to output it into any format you could want.
For example:
var dateOld = "11/27/2010",
dateArr = date1.split("/"),
dateObj = new Date(dateArr[2], dateArr[0], dateArr[1]),
dateNew = dateObj.f("MMM d, yyyy");
document.write("Old Format: " + dateOld + "<br/>New Format: " + dateNew);

This works fine for me:
<%
Date date = Calendar.getInstance().getTime();
%>
<script>
var d = new Date(<%=date.getTime()%>);
alert(d);
</script>

I suggest you the MomentJS with this Plugin that allow you to convert a Java pattern to a JS pattern (MomentJS)

On Java Side
I recommend passing an Instant string which conforms to ISO 8601 standard.
import java.time.Instant;
class Main {
public static void main(String[] args) {
Instant instant = Instant.now();
// You can pass the following string to JavaScript
String strInstant = instant.toString();
System.out.println(strInstant);
// If the number of milliseconds from epoch is required
long millis = instant.toEpochMilli();
System.out.println(millis);
}
}
Output from a sample run:
2022-12-31T09:40:52.280726Z
1672479652280
ONLINE DEMO
Learn more about the modern Date-Time API from Trail: Date Time.
On JavaScript Side
Now, you can parse the ISO 8601 string on the JavaScript side simply by passing it as a parameter to Date constructor. You can also instantiate the Date object with the number of milliseconds from the epoch.
var date = new Date("2022-12-31T09:40:52.280726Z");
console.log(date.toISOString());
// Or if the number of milliseconds from epoch has been received
date = new Date(1672479652280);
console.log(date.toISOString());

The javascript code in this page implements some date functions and they "use the same format strings as the java.text.SimpleDateFormat class, with a few minor exceptions". It is not the very same as you want but it can be a good start point.

If you just want to format dates my date extensions will do that well - it also parses data formats and does a lot of date math/compares as well:
DP_DateExtensions Library
Not sure if it'll help, but I've found it invaluable in several projects.

If you are using java, take a look at the Simple Date Format class.

Related

How to manipulate date time using vanilla javascript

I want to manipulate date which come from the api.
When I use: console.log(dataAPI.dateStation)
I see 2023-01-24T06:00:00.000Z
Is there way to change the date time in this format 2023-01-24 06:00:00
Just I want to remove T character between date and time and remove .000Z at the end.
The simplest way to do it is probably:
new Date(dataAPI.dateStation).toLocaleString()
If what you want is to display it somewhere, it'll automatically adapt the ISO date you have into a localized and readable date (based on timezone and language).
To know more about it and the options, here is the doc: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleString
If you want to print the date in ISO 8601 format, you can use the 'sv' (Sweden) locale and Date.toLocaleString().
You can also specify whichever IANA timezone you wish to use, I'm using UTC in this case.
const d = '2023-01-24T06:00:00.000Z'
let timestamp = new Date(d).toLocaleString('sv', { timeZone: 'UTC' });
console.log('Timestamp:', timestamp);
Use the javascript date class with toLocaleString
new Date(dataAPI.dateStation).toLocaleString('en-US');
Without installing some third-party library, your best bet is probably to use the string you have (which is the format returned by toISOString() ),and modify it as desired. If it's already a string in the format you gave, you can just call replace on it:
dataAPI.dateStation.replace('T',' ').replace('.00Z','')
If it's a Date object, first call toISOString() to get a string:
dataAPI.dateStation.toISOString().replace('T',' ').replace('.00Z','')
If it's a string in a possibly-different format, call new Date() to get a Date object, then call toISOString() on that, and finally call replace on the result:
new Date(dataAPI.dateStation).toISOString().replace('T',' ').replace('.00Z','')
You can use regular expressions to remove the parts you don't want:
let s = "2023-01-24T06:00:00.000Z"
s = s.replace(/T/, ' ')
s = s.replace(/\.\d{3}Z$/, '')
console.log(s)

how to format date pulled from database(inserted as new Date() )

I'm not so sure what's the proper way to insert date into the database, but I'm using new Date().
So I get date format like this when I query from the database:
2021-09-24T12:38:54.656Z
Now I realized that date format is not so user-friendly. So I'm trying to convert it if possible standard readable format like this:
Sept 25 2015, 8:00 PM
I tried using toLocaleString() to my date pulled from db but it won't work probably if I got it correctly pulled date from the db is already a string?
Is there a workaround for this so that I don't need to change how I enter date to my db?
const date = moment("2021-09-24T12:38:54.656Z").format('MMM D YYYY, h:mm a')
console.log(date)
<script src="https://momentjs.com/downloads/moment.min.js"></script>
use momentjs
You can find format method and apply as you desire
https://momentjs.com/
I think it is better to store in DB as UTC 00 value and you are doing it right now.
When you retrieve it, you will be getting a string value something like, 2021-09-24T12:38:54.656Z. On the UI you can easily convert it to date variable in JS using,
const dateVar = new Date("2021-09-24T12:38:54.656Z");
console.log(dateVar.toLocaleString());
If you want more date formatting other than the inbuild solutions like toLocaleString you can use date libraries like moment.js
You'd need to create a Date object from the timestamp string like this.
let date = new Date('2021-09-24T12:38:54.656Z');
Then you can use toLocaleString, toLocaleDateString, toDateString, or toString as you see fit.

Convert YYYY-MM-DD HH:MM:SS to different format in Javascript

I have a string in javascript as 2016-02-27 20:24:39 and I want to convert this as 27th Feb 08:24pm.
What is the easiest way to do in Javascript?
Checkout the JavaScript library called moment.js.
Since the default format for moment is ISO 8601 (YYYY-MM-DD HH:MM:SS), you don't need to tell moment how to parse the input String date (it defaults to ISO 8601), so you can simply write:
var now = "2016-02-27 20:24:39";
var formattedDate = moment(now).format("Do MMM HH:mma");
console.log(formattedDate);
Demo:
https://jsfiddle.net/gekd97dy/
More information about displaying in different formats can be read here:
http://momentjs.com/docs/#/displaying/
There is a non-standard Date method toLocaleFormat('%d-%b-%Y'). But appears to only work in Firefox for now.
Better use the date.format library (only 125 lines)
var date = new Date('2016-02-27 20:24:39');
dateFormat(date, "dS mmm, h:MMTT");

Convert string to Date?

I want to compare these Strings2013-11-04 13:10:22.0, 2013-11-04 13:08:03.0 through JavaScript, jQuery or any other library. Is there any way to convert these Strings into Date Type?
I searched this in google and Stack Overflow and found that JavaScript is not good at DateTime formats.
Actually I get JSON data from Server through jQuery.Ajax, My JSON object looks like this
{"RecieverEmail": "email#gmail.com",
"Message": "Hello Ankit",
"DateTime": "2013-11-04 13:08:03.0"
}
and when I parse this Date format using Date.parse method
var d = Date.parse(data.DateTime);
alert(d);
it alerts 1383550683000
Moment.js is a great library for this: http://momentjs.com/
You can pass that exact string in and format it the way you want or call .toDate()on it to get a JavaScript date object.
Parse like this
var d = new Date(data.DateTime);
alert(d);
because the Date.parse() method parses a string representation of a date, and
returns the number of milliseconds
Please use "Momment.js" . It is the free version and it is very simple to handle this type of operation.
http://momentjs.com/
Let the Date be "2013-11-04" make it to a Date Object as
var d=new Date(Date.parse("2013-11-04"));
for compare you can use this number because Date.parse return the number of milliseconds since January 1, 1970, 00:00:00 UTC.
Try this
var d = Date.parse(data.DateTime);
var realDate = new Date(d);
alert(realDate);
There are quite a few good jQuery plugins out there that make dealing with dates a little bit easier. I would also recommend Moment.js since it is the easier to use and more flexible in my opinion.
Here is a fiddle that converts your json datetime into a date object
http://jsfiddle.net/kLMMg/1/
Its as simple as:
var a = {"RecieverEmail": "email#gmail.com",
"Message": "Hello Ankit",
"DateTime": "2013-11-04 13:08:03.0"
}
alert(new Date(a.DateTime))

Moment.js transform to date object

Using Moment.js I can't transform a correct moment object to a date object with timezones. I can't get the correct date.
Example:
var oldDate = new Date(),
momentObj = moment(oldDate).tz("MST7MDT"),
newDate = momentObj.toDate();
console.log("start date " + oldDate)
console.log("Format from moment with offset " + momentObj.format())
console.log("Format from moment without offset " + momentObj.utc().format())
console.log("(Date object) Time with offset " + newDate)
console.log("(Date object) Time without offset "+ moment.utc(newDate).toDate())
Use this to transform a moment object into a date object:
From http://momentjs.com/docs/#/displaying/as-javascript-date/
moment().toDate();
Yields:
Tue Nov 04 2014 14:04:01 GMT-0600 (CST)
As long as you have initialized moment-timezone with the data for the zones you want, your code works as expected.
You are correctly converting the moment to the time zone, which is reflected in the second line of output from momentObj.format().
Switching to UTC doesn't just drop the offset, it changes back to the UTC time zone. If you're going to do that, you don't need the original .tz() call at all. You could just do moment.utc().
Perhaps you are just trying to change the output format string? If so, just specify the parameters you want to the format method:
momentObj.format("YYYY-MM-DD HH:mm:ss")
Regarding the last to lines of your code - when you go back to a Date object using toDate(), you are giving up the behavior of moment.js and going back to JavaScript's behavior. A JavaScript Date object will always be printed in the local time zone of the computer it's running on. There's nothing moment.js can do about that.
A couple of other little things:
While the moment constructor can take a Date, it is usually best to not use one. For "now", don't use moment(new Date()). Instead, just use moment(). Both will work but it's unnecessarily redundant. If you are parsing from a string, pass that string directly into moment. Don't try to parse it to a Date first. You will find moment's parser to be much more reliable.
Time Zones like MST7MDT are there for backwards compatibility reasons. They stem from POSIX style time zones, and only a few of them are in the TZDB data. Unless absolutely necessary, you should use a key such as America/Denver.
.toDate did not really work for me, So, Here is what i did :
futureStartAtDate = new Date(moment().locale("en").add(1, 'd').format("MMM DD, YYYY HH:MM"))
hope this helps
Since momentjs has no control over javascript date object I found a work around to this.
const currentTime = new Date();
const convertTime = moment(currentTime).tz(timezone).format("YYYY-MM-DD HH:mm:ss");
const convertTimeObject = new Date(convertTime);
This will give you a javascript date object with the converted time
The question is a little obscure. I ll do my best to explain this. First you should understand how to use moment-timezone. According to this answer here TypeError: moment().tz is not a function, you have to import moment from moment-timezone instead of the default moment (ofcourse you will have to npm install moment-timezone first!). For the sake of clarity,
const moment=require('moment-timezone')//import from moment-timezone
Now in order to use the timezone feature, use moment.tz("date_string/moment()","time_zone") (visit https://momentjs.com/timezone/ for more details). This function will return a moment object with a particular time zone. For the sake of clarity,
var newYork= moment.tz("2014-06-01 12:00", "America/New_York");/*this code will consider NewYork as the timezone.*/
Now when you try to convert newYork (the moment object) with moment's toDate() (ISO 8601 format conversion) you will get the time of Greenwich,UK. For more details, go through this article https://www.nhc.noaa.gov/aboututc.shtml, about UTC. However if you just want your local time in this format (New York time, according to this example), just add the method .utc(true) ,with the arg true, to your moment object. For the sake of clarity,
newYork.toDate()//will give you the Greenwich ,UK, time.
newYork.utc(true).toDate()//will give you the local time. according to the moment.tz method arg we specified above, it is 12:00.you can ofcourse change this by using moment()
In short, moment.tz considers the time zone you specify and compares your local time with the time in Greenwich to give you a result. I hope this was useful.
To convert any date, for example utc:
moment( moment().utc().format( "YYYY-MM-DD HH:mm:ss" )).toDate()
let dateVar = moment('any date value');
let newDateVar = dateVar.utc().format();
nice and clean!!!!
I needed to have timezone information in my date string. I was originally using moment.tz(dateStr, 'America/New_York').toString(); but then I started getting errors about feeding that string back into moment.
I tried the moment.tz(dateStr, 'America/New_York').toDate(); but then I lost timezone information which I needed.
The only solution that returned a usable date string with timezone that could be fed back into moment was moment.tz(dateStr, 'America/New_York').format();
try (without format step)
new Date(moment())
var d = moment.tz("2019-04-15 12:00", "America/New_York");
console.log( new Date(d) );
console.log( new Date(moment()) );
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/moment.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment-timezone/0.5.23/moment-timezone-with-data.min.js"></script>
moment has updated the js lib as of 06/2018.
var newYork = moment.tz("2014-06-01 12:00", "America/New_York");
var losAngeles = newYork.clone().tz("America/Los_Angeles");
var london = newYork.clone().tz("Europe/London");
newYork.format(); // 2014-06-01T12:00:00-04:00
losAngeles.format(); // 2014-06-01T09:00:00-07:00
london.format(); // 2014-06-01T17:00:00+01:00
if you have freedom to use Angular5+, then better use datePipe feature there than the timezone function here. I have to use moment.js because my project limits to Angular2 only.
new Date(moment()) - could give error while exporting the data column in excel
use
moment.toDate() - doesn't give error or make exported file corrupt

Categories

Resources