Develop Reference

How can i customize the js new Date() instance

When i use the new Date() instance i get something like
2020-12-10T12:30:18.108Z
the problem is that by me the hour on my local machine is 13:30 - but it gives me one hour earlier so 12:30 in the current time. How can i customize to give me the right time of my local machine ?
Also i don't know the meaning of the last four character after the . sign
108Z
all i need is to insert in my db the hour and the date without this signs
2020-12-10T12:30:18
is there any other solution except manupulating the string directly ?

You're using UTC Date I guess. You can try to use .toLocaleString() on your date time object.
Maybe use like that
var datetime = new Date();
var now = datetime.toLocaleString();
This should get you something like this: 10/12/2020, 8:47:15 AM
UPDATED
Another option if you want to maintain format and just remove T and Z characters is to replace string
You can try this:
var datetime = new Date();
var now = datetime.toISOString().replace('Z', '').replace('T', '');

How can I extract date and time from php variable in javascript?

I have a quastion.
So I get from server a variable with date-time string which looks like this: '31/08/2015 13:24'.
How can extract from this string separately date and time?

You could split the string:
var dateTime = '31/08/2015 13:24'.split(" ");
console.log(dateTime[0]); //date
console.log(dateTime[1]); //time
Or use js Date object to get the day, month, year, hours, etc:
var dateTime = new Date('31/08/2015 13:24');

How to get date format in Angular-JS

My requirement is something different. I want to get the date format, not to format the date. Means I have a date string and now I want to get the date format of that date and apply it to the another date as a format.
Let me explain in brief with example:
var dateStr = "2015-06-06T12:00:00Z";
var d = new Date(dateStr);
here my date format is yyyy-MM-ddTHH:mm:ssZ you can see in dateStr object.
Now i will create another date and want to apply the same date-format to this new date.
var formatStr = "yyyy-MM-dd'T'HH:mm:ss'Z'"; // want to get this from above date, not hard coded like this.
var newDate = $filter('date')(d, formatStr);
here you can see that i have hard coded the format string, which i don't want to do. Here this string should be come from the above d date/or dateStr String.

You can do it by using momment.js
http://momentjs.com/downloads/moment.js
van date=new Date(date);
var dateInFormate=moment(date);
var date=dateInFormate.format('yyyy-MM-ddTHH:mm:ssZ');

As #Rob said, there is doubt on the reliably for all formats. What you need is pre defined map with key being the format and value being its corresponding regular expression.
Now, create a function with input as dateStr and will return the format. Like
function getDateFormat(dateStr) {
var format = default_format;
// Check in map for format
// If you get the format in map, return that else return a default format.
return format;
}

How to get the date object

My value contains "08.07.1987", how to retrieve the date object for this string. new Date(val) gives correct date object values only for the string value that contains "/" format. can any one let me know hot to create date object for the values which contains "." or "-". in its format.

How about just adjusting the string to suit your needs?
var date1 = new Date("08.07.1987".replace('.','/'));
var date2 = new Date("08-07-1987".replace('-','/'));
You will need to be careful when asking Javascript to interpret a date in this format. As you can probably imagine, a date listed as "08.07.1987" doesn't really specify whether it's August 7th or July 8th.
In general, your best bet will be to specify a date format and parse accordingly.

you have to split the string into tokens for month date and year and then create it using JS Date API.

var date="08.07.1987";
var newDate = date.replace(/(\.|-)/g,"/"));
var dateObject = new Date(newDate);

Replace the delimiters?
var dateStr = "08.07.1987",
dateObj = new Date(dateStr.replace(/[-.]/g,"/"));
Of course you can encapsulate that in a function if need be...

try this new Date("08.07.1987".replace('.','/','g')); tested on firefox only

How to parse the year from this date string in JavaScript?

Given a date in the following string format:
2010-02-02T08:00:00Z
How to get the year with JavaScript?

It's a date, use Javascript's built in Date functions...
var d = new Date('2011-02-02T08:00:00Z');
alert(d.getFullYear());

You can simply parse the string:
var year = parseInt(dateString);
The parsing will end at the dash, as that can't be a part of an integer (except as the first character).

I would argue the proper way is
var year = (new Date('2010-02-02T08:00:00Z')).getFullYear();
or
var date = new Date('2010-02-02T08:00:00Z');
var year = date.getFullYear();
since it allows you to do other date manipulation later if you need to and will also continue to work if the date format ever changes.
UPDATED: Jason Benson pointed out that Date will parse it for you. So I removed the extraneous Date.parse calls.

var year = '2010-02-02T08:00:00Z'.substr(0,4)
...
var year = new Date('2010-02-02T08:00:00Z').getFullYear()

You can simply use -
var dateString = "2010-02-02T08:00:00Z";
var year = dateString.substr(0,4);
if the year always remain at the front positions of the year string.