Develop Reference

How to get tomorrow's date of a specific date

I am trying to get tomorrow's date of a specific date using JavaScript in format (yyyy-mm-dd). For example the specific date is 2021-08-31 and I have got this script:
var date = "2021-08-31"
date = new Date(date.split("-")[0],date.split("-")[1],date.split("-")[2])
date.setDate(date.getDate() + 1);
var tomorrows_date_month = date.getMonth()
var tomorrows_date_day = date.getDate()
var tomorrows_date_year = date.getFullYear()
console.log(tomorrows_date_year + "-" + tomorrows_date_month + "-" + tomorrows_date_day)
The expected output is:
2021-09-01
But the output of this code is :
2021-9-2

First you don't need split "2021-08-31" to use as date parameter, so just use new Date("2021-08-31");
Second note that you need to use d.getMonth() + 1 and add leading zero if the length is less than 2:
Try this one:
function formatDate(date) {
var d = new Date(date),
month = '' + (d.getMonth() + 1),
day = '' + d.getDate(),
year = d.getFullYear();
if (month.length < 2)
month = '0' + month;
if (day.length < 2)
day = '0' + day;
return [year, month, day].join('-');
}
Date.prototype.addDays = function(days) {
var date = new Date(this.valueOf());
date.setDate(date.getDate() + days);
return date;
}
var date = "2021-08-31"
var date1 = new Date(date);
console.log(formatDate(date1.addDays(1)));

Internally js month is stored as a value between 0 and 11. So you need to minusdate.split("-")[1] by 1. Otherwise, javascript will think that your month is actually September and we know that "2021-09-32" is translated to "2021-10-2", therefore the date is shown as "2".
var date = "2021-08-31"
date = new Date(date.split("-")[0],date.split("-")[1] - 1,date.split("-")[2])
date.setDate(date.getDate() + 1)
var tomorrows_date_month = date.getMonth() + 1
var tomorrows_date_day = date.getDate()
var tomorrows_date_year = date.getFullYear()
console.log(tomorrows_date_year + "-" + tomorrows_date_month + "-" + tomorrows_date_day)
Also note that date = new Date("2021-08-31") is enough for converting a string into a Date object.

new Date(new Date(date + 'T00:00Z').getTime() + 86400000).toISOString().substr(0, 10)
The added 'T00:00Z' assures the date is parsed as UTC, to match the UTC timezone used by toISOString(). Adding 86400000 (the number of milliseconds in one day) advances the date without having to fuss with the date field directly.

How to format existing date using JavaScript/jQuery

I am trying to format date time using JavaScript/jQuery but it's not happening. My code is below.
<div id="divID"></div>
<script>
var formatDate = function(date){
return date.getDate() + "/" + date.getMonth() + "/" +date.getYear() + " "+ date.getHours() + ":" + date.getMinutes() + ":" + date.getMintutes() + ":" + date.getSeconds();
}
var timestamp="2016-12-16 07:58:30 AM ";
var date= new Date(timestamp);
document.getElementById('divID').innerHTML = formatDate(date);
</script>
Here I have the existing time 2016-12-16 07:58:30 AM and I need change it to 16-12-2016 07:58:30 AM but here I could not get the proper output.

Your code has a few issues:
You have a syntax error, you're calling getMintutes()
You appear to be attempting to show the minutes twice, so you can remove one of those calls
getFullYear() fits your needs better than getYear()
You should use - not / to delimit the date values.
You can add AM or PM to the end of the string by checking if hours < 12
Your timestamp string isn't valid. It should not contain 'AM' or 'PM' - hence why the code doesn't work in Firefox.
With that in mind, try this:
var formatDate = function(date) {
return date.getDate() + "-" + date.getMonth() + "-" + date.getFullYear() + " " + ('0' + date.getHours()).slice(-2) + ":" + ('0' + date.getMinutes()).slice(-2) + ":" + ('0' + date.getSeconds()).slice(-2) + ' ' + (date.getHours() < 12 ? 'AM' : 'PM');
}
var timestamp = "2016-12-16 07:58:30";
var date = new Date(timestamp);
document.getElementById('divID').innerHTML = formatDate(date);
<div id="divID"></div>
You could use a library to make the date formatting logic simpler, but it's rather wasteful to load an entirely library when a single line of code works fine.

The timestamp you are using will return an invalid date so you should remove the AM. Using moment.js you can do it like this:
var timestamp = "2016-12-16 07:58:30";
var formattedDate = moment(timestamp).format('DD-MM-YYYY h:mm:ss A');
console.log(formattedDate);
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.5.1/moment.min.js"></script>

you can use a library named moment.js http://momentjs.com/
var date = new Date();
moment(date).format('DD-MM-YYYY HH:mm:ss A')

jQuery dateFormat is a separate plugin. You need to load that explicitly using a <script> tag.

You can use JQuery UI Datepicker for getting the formatted date like the following.
let myDate = '2020-11-10';
$.datepicker.formatDate('dd-M-yy', new Date(myDate));
The above code will return 10-Nov-2020.

You can get the desired output using JQuery UI Datepicker Widget as shown below.
var timestamp="2016-12-16 07:58:30 AM ";
var desiredTimestamp = $.datepicker.formatDate('dd-mm-yy', new Date(timestamp.split(' ')[0])) + ' ' + timestamp.split(' ')[1] + ' ' + timestamp.split(' ')[2];

How to get the date one month before from current date, when current date is January?

I used a plugin called jQRnageSlider and tried to get the date and time label showed in the slider, but when I scroll back the slider to last year, the month 12 turns out to be 11 eventually.
Normal case if I don't scroll back to last year.
It jumped to Nov 2016 immediately
That should be the issue of date formatting issue. Can anyone help?
$(".date-range-slider").dateRangeSlider({
...
formatter: function(val){
var days = ('0' + val.getDate()).slice(-2),
month = ('0' + val.getMonth() + 1).slice(-2),
year = val.getFullYear(),
hour = ('0' + val.getHours()).slice(-2),
min = ('0' + val.getMinutes()).slice(-2);
return days + "-" + month + "-" + year + " " + hour + ":" + min;
}
});

The problem is that line:
month = ('0' + val.getMonth() + 1).slice(-2)
You want to sum it mathematically not as string, so you should do:
month = ('0' + (val.getMonth() + 1)).slice(-2)
Check the snippet to see what your code is actually returning:
var val = new Date();
document.write('0' + val.getMonth() + 1)
And what returns corrected version:
var val = new Date();
document.write('0' + (val.getMonth() + 1))

Date parse format from T with time to mm/dd/yyyy with javascript or jquery

I have the following value:
javascript variable:
"2015-10-14T17:54:19.033"
I want to end up with
mm/dd/yyyy
e.g.
10/14/2015
I was trying to do
var date = month[d.getMonth()] + " " + d.getDay()+ ", " + d.getFullYear();
Here is my Fiddle
http://jsfiddle.net/bthorn/7ptcedt4/
var d = new Date('2015-10-14T17:54:19.033');
var date = d.getMonth().toString() + "/" + d.getDay().toString() + "/" + d.getFullYear().toString();
console.log(date);
Something is NOT right: I am getting
9/3/2015

You can use this:
var date = new Date("2015-10-14T17:54:19.033");
var formatedDateString = (date.getMonth() + 1) + '/' + date.getDate() + '/' + date.getFullYear();
Or use moment.js
var formatedDateString = moment("2015-10-14T17:54:19.033").format('MM/dd/YYYY');
Or may you consider create your own date format function.
PS.: javascript months are 0-indexed, so for the correct month you should use (date.getMonth() + 1)

Getting the date from Javascript comes up with bizarre values

I want to get the date and time in the following format:
yyyy.mm.dd.hh.mm.ss | 2014.11.6.20.31.24
However, my code (based on Get Current Time) is instead providing these values:
y??.m?.d?.hh.mm.ss | 114.10.4.20.31.24
Here is my code:
var dt = new Date();
var time = dt.getHours() + "." + dt.getMinutes() + "." + dt.getSeconds();
var date = dt.getYear() + "." + dt.getMonth() + "." + dt.getDay();
alert(date + "." + time);
Can someone please let me know why these odd values are in there 114.10.4 and how to change them to be what I want?

That is because you need to use
.getFullYear() for the full year
the .getMonth() is 0-based so you need to add 1
the function to get the day of month is .getDate(). The .getDay() is for the day of the week.
var dt = new Date();
var time = dt.getHours() + "." + dt.getMinutes() + "." + dt.getSeconds();
var date = dt.getFullYear() + "." + (dt.getMonth()+1) + "." + dt.getDate();
alert(date + "." + time);
If, for some weird reason, you are going only for firefox, you can use
var d = new Date(),
formatted = d.toLocaleFormat('%Y.%m.%d.%H.%M.%S');
alert(formatted);
Finally, you can use the great moment.js library and do
var formatted = moment().format('YYYY.MM.DD.HH.mm.ss');

You are using the wrong getters. Use getFullYear() instead of getYear(), and getDate() instead of getDay(). And add 1 to the month, because it starts at 0.
var dt = new Date();
var time = dt.getHours() + "." + dt.getMinutes() + "." + dt.getSeconds();
var date = dt.getFullYear() + "." + (dt.getMonth() + 1) + "." + dt.getDate();
alert(date + "." + time);

Just make sure that you are using methods what you want to use e.g:
dt.getYear() => dt.getFullYear()
For further reference see this.

should use getFullYear() instead of getYear() and getMonth() + 1 instead of getMonth() because it calculate form 0..11 and info about getDay()
var dt = new Date();
var time = dt.getHours() + "." + dt.getMinutes() + "." + dt.getSeconds();
var date = dt.getFullYear() + "." + dt.getMonth() + 1 + "." + dt.getDate();
alert(date + "." + time);
dt.getDay() this day of the week

The getDay() method returns the day of the week (from 0 to 6)
You need to use getDate() to know the number of the day (from 1 to 31)
Also, you need to add 1 to getMonth() because months in JavaScript starts on 0