Develop Reference

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.

Kind of time (yyyymmddThhmmZ)

I'm trying to generate links to Google calendar and see this tool:
https://decomaan.github.io/google-calendar-link-generator/
And the links are generated as:
https://www.google.com/calendar/render?action=TEMPLATE&text=Appointment+with+VULKOVICH%2C+BILL&details=a+Description&location=a+Location&dates=20210105T103300Z%2F20210114T103300Z
and as you can see the dates are like:
20210105T103300Z
and I am trying to convert this to my own dates but I don't know which type is this and how to format. I have the dates both, in moment or in date, but don't know how to convert.

That's ISO-8601
The first part is the date in year-month-date order, the second part is the time and the final letter indicates the timezone (here Z for 'Zulu')

Since you're using moment.js: moment().utc().format('YYYYMMDDTHHmmss[Z]'), or without a library new Date().toISOString().replace(/\W/g,'').replace(/\d{3}Z/,'Z'). This is really a duplicate of How to format a JavaScript date.
Source: comment by RobG Jan 11 at 12:58

How to add time zone to specific format in momentjs?

I am trying to get specific format of datetime with time zone
i am getting string of time format which is shown below
var dateTime = "2020-06-01T01:50:57.000Z CDT"
I need to convert the format in to
const offsetTime = moment(date).add("-0.00", 'hours')
const formatedDate = moment(offsetTime, 'h:mm:ss A')
.utc()
.format('h:mm A')//(1:50 AM)
Required output
(1:50 AM CDT)
Do i need to split the string and get the format or do we have any method to convert it to this format in momentjs
In simple way to say
YYYY-MM-DDTHH:mm:ss.SSS[Z] z To hh:mm A z //format
and if the string contains only 2 character like "CT" instead of CDT how to capture that.

You can zz to get timezone in output. For ex:
moment()..format('h:mm A zz')
More documentation here momentJS

Use the moment-timezone to achieve this. Use the moment constructor to specify the input format, then specifying the required timezone. Finally use moment's format to get the required format
var dateTime = "2020-06-01T01:50:57.000Z CDT";
var timezone = "America/Chicago";
console.log(
moment(dateTime, "YYYY-MM-DD hh:mm:ss zz")
.tz(timezone)
.format("h:mm A zz")
);
<script src="https://momentjs.com/downloads/moment.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment-timezone/0.5.23/moment-timezone-with-data-2012-2022.min.js"></script>

Your date string is in ISO format with the 'Z' after seconds indicating that it is in UTC time. I am assuming that the 'CDT' is placed in the string in order to indicate which time zone this should be converted to. If you have control over how this string is represented then I recommend changing it so that you indicate the desired timezone elsewhere and simply store the date in UTC format. This way you can initialize a date or moment object with the ISO string as follows:
var date = moment("2020-06-01T01:50:57.000Z")
It is inconvenient the way it is currently since you cannot initialize it this way:
var date = moment("2020-06-01T01:50:57.000Z CDT")
The only option for handling the date in its current form is to parse it. You can do that like this:
var dateTime = "2020-06-01T01:50:57.000Z CDT"
var trimmed = dateTime.trim() // remove leading and trailing whitespace
var isoString = trimmed.substr(0, trimmed.indexOf(' '))
Which will produce the following string
2020-06-01T01:50:57.000Z
You can use that string I called "isoString" to initialize a date or moment object. The next obstacle is to handle converting that UTC string to a certain timezone (in this case CDT). It is simple if you want to convert the UTC date to the current users timezone since that will happen automatically when you initialize the moment or date object with the ISO date string. Otherwise, you need some way to get the timezone from 'CDT' into the format moment wants which was shown by #vjr12 ("America/Chicago"). The only way to do this is to either store that with the date string or create a mapping. It is much easier to convert from "America/Chicago" to "CDT" than it is to convert from "CDT" to "America/Chicago". Your only option with the current form is to create your own mapping from "CDT" to "America/Chicago". You could do something like:
let tzMap = new Map()
tzMap.set('CDT','America/Chicago')
// Set the rest of your timezones
You would need to do that for all timezones and then you could use the timezone parsed from your date string like this:
var tzAbbr = trimmed.substr(trimmed.indexOf(' ') + 1)
which will grab the "CDT" or "CT" for that matter. Then you could use your mapping like this:
var timezone = tzMap.get(tzAbbr)
timezone will be "America/Chicago" in this case and then you can use #vjr12 solution from here to get the form you want.
Note
I highly recommend that (if you are able) to change the current format of the datestring that you are using. The purpose of using UTC time is to be timezone agnostic so it does not make sense to store the timezone with the UTC string. If you want to preserve the timezone then you would be better off using a format which already embeds the timezone.

momentjs change string mm/yyyy format to yyyy-mm

I have a date string 11/2004 that comes to me via an API and on mobile I am trying to display this on a date field.
If i try to render this as it is I see the following warning on console
The specified value "11/2004" does not conform to the required format.
The format is "yyyy-MM" where yyyy is year in four or more digits, and
MM is 01-12.
so using momentjs i thought this should be easy to change to date or month format but i am struggling with it as i cant seem to get the output i want.
I tried the following code but that give me invalid date
moment('11/2004').format('yyyy-MM')
What am i doing wrong here? How do i display the date on an input field in the correct format? I cant change the field type to anything else as its a date picker field on mobile.

Looking at the documentation on parsing what you need to do is created your moment object with the format specified.
moment('11/2004','MM/YYYY')
This will set the day to the first, but the month and the year to the ones specified.
Also, your format is wrong, the yyyy should be capital YYYY
So your final code should look like this
moment('11/2004', 'MM/YYYY').format('YYYY-MM')

You should create your date with the string-format
moment('11/2004', 'MM/YYYY')
and then display it using the format() function
moment('11/2004', 'MM/YYYY').format('YYYY-MM')

8601 ISO String to readable date format in Javascript

I'm having a pretty horrid time trying to convert an 8601 into a readable format. The date shows as 'P0DT0H0M10S' and is stored in a var called timeLeft. Every article I find online tells me how to turn dates INTO the 8601 format, but not the other way around.
I tried using moment.js but that seems to revolve around the current date and not one set by my timeLeft var. How do I get this var into a user-friendly format? Thanks

Moment has a duration type:
var duration = moment.duration('P1Y2M3DT4H5M6S');
// user-friendly format
var out = duration.humanize();
snippet.log(out);
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.11.1/moment.min.js"></script>
<script src="https://tjcrowder.github.io/simple-snippets-console/snippet.js"></script>

First off, that's not an ISO-8601 date (not even close).
Second, momentjs does support parsing a string into a moment, with the moment("20111031", "YYYYMMDD") syntax (from their front page examples).
I'm not sure what the pattern you need would be, but maybe something like [P]D[DT]H[H]M[M]S[S].