How can I convert string to datetime with format specification in JavaScript?

Use new Date(dateString) if your string is compatible with Date.parse(). If your format is incompatible (I think it is), you have to parse the string yourself (should be easy with regular expressions) and create a new Date object with explicit values for year, month, date, hour, minute and second.

I think this can help you: http://www.mattkruse.com/javascript/date/

There's a getDateFromFormat() function that you can tweak a little to solve your problem.

Update: there's an updated version of the samples available at javascripttoolbox.com

No sophisticated date/time formatting routines exist in JavaScript.

You will have to use an external library for formatted date output, "JavaScript Date Format" from Flagrant Badassery looks very promising.

For the input conversion, several suggestions have been made already. :)

Date.parse() is fairly intelligent but I can't guarantee that format will parse correctly.

If it doesn't, you'd have to find something to bridge the two. Your example is pretty simple (being purely numbers) so a touch of REGEX (or even string.split() -- might be faster) paired with some parseInt() will allow you to quickly make a date.

You can use the moment.js library for this. I am using only to get time-specific output but you can select what kind of format you want to select.

Reference:

1. moment library: https://momentjs.com/

2. time and date specific functions: https://timestamp.online/article/how-to-convert-timestamp-to-datetime-in-javascript

convertDate(date) {
        var momentDate = moment(date).format('hh : mm A');
        return momentDate;
}

and you can call this method like:

this.convertDate('2020-05-01T10:31:18.837Z');

I hope it helps. Enjoy coding.

//Here pdate is the string date time
var date1=GetDate(pdate);
    function GetDate(a){
        var dateString = a.substr(6);
        var currentTime = new Date(parseInt(dateString ));
        var month =("0"+ (currentTime.getMonth() + 1)).slice(-2);
        var day =("0"+ currentTime.getDate()).slice(-2);
        var year = currentTime.getFullYear();
        var date = day + "/" + month + "/" + year;
        return date;
    }