What does this format means T00:00:00.000Z?

Can someone, please, explain this type of format in javascript

 T00:00:00.000Z

And how to parse it?

It's a part of ISO-8601 date representation. It's incomplete because a complete date representation in this pattern should also contains the date:

2015-03-04T00:00:00.000Z //Complete ISO-8601 date

If you try to parse this date as it is you will receive an Invalid Date error:

new Date('T00:00:00.000Z'); // Invalid Date

So, I guess the way to parse a timestamp in this format is to concat with any date

new Date('2015-03-04T00:00:00.000Z'); // Valid Date

Then you can extract only the part you want (timestamp part)

var d = new Date('2015-03-04T00:00:00.000Z');
console.log(d.getUTCHours()); // Hours
console.log(d.getUTCMinutes());
console.log(d.getUTCSeconds());

i suggest you use moment.js for this. In moment.js you can:

var localTime = moment().format('YYYY-MM-DD'); // store localTime
var proposedDate = localTime + "T00:00:00.000Z";

now that you have the right format for a time, parse it if it's valid:

var isValidDate = moment(proposedDate).isValid();
// returns true if valid and false if it is not.

and to get time parts you can do something like:

var momentDate = moment(proposedDate)
var hour = momentDate.hours();
var minutes = momentDate.minutes();
var seconds = momentDate.seconds();

// or you can use `.format`:
console.log(momentDate.format("YYYY-MM-DD hh:mm:ss A Z"));

More info about momentjs http://momentjs.com/