Javascript Date UTC issue

Question

Here I am trying to convert a date to UTC and then converting same UTC date as new date. but the issue is that I am not getting same date which I passed. here is my fiddle

Here I am passing Date 11/2/2015 ie 2 November 2015, then converting it to UTC format, then UTC to normal date using new Date but now it is returning me 11/1/2015 ie 1 November 2015.

Thanks in advance.

var myDate = '11/2/2015';
var myDateObj = new Date(myDate);
console.log('my Date is \n' + myDateObj);

var tempDate = Date.UTC(myDateObj.getFullYear(),myDateObj.getMonth(),myDateObj.getDay());
var utcDate = new Date(tempDate);

console.log('my Date after utc \n' + utcDate);

Answer 1

The getDay() method does not return the day of the month see more at js Date.getDay() so instead of that you need to pass the day of the month which you can get by getDate() see more at getDate()

var myDate = '11/2/2015';
var myDateObj = new Date(myDate);
console.log('my Date is \n' + myDateObj);

var tempDate = Date.UTC(myDateObj.getFullYear(),myDateObj.getMonth(),myDateObj.getDate());
var utcDate = new Date(tempDate);
console.log('my Date after utc \n' + utcDate);

Answer 2

I Used

myDateObj.getDate()

and it is working fine and please check now.

var myDate = '11/02/2015';
var myDateObj = new Date(myDate);
console.log('my Date is \n' + myDateObj);
console.log('my Date is \n' + myDateObj.getDate());

var tempDate = Date.UTC(myDateObj.getFullYear(),myDateObj.getMonth(),myDateObj.getDate());
var utcDate = new Date(tempDate);

console.log('my Date after utc \n' + utcDate);

Answer 3

This happens because it first converts the date to the long value as in milliseconds then to the date so 2nd november 00:00:00 it can take as 1st november 23:30:00 so you can give time also in the date as follow :

var myDate = '11/2/2015 23:00:00';
var myDateObj = new Date(myDate);
console.log('my Date is \n' + myDateObj);

var tempDate = Date.UTC(myDateObj.getFullYear(),myDateObj.getMonth(),myDateObj.getDay(),myDateObj.getHours(),myDateObj.getMinutes(),myDateObj.getSeconds());
var utcDate = new Date(tempDate);
console.log('my Date after utc \n' + utcDate);

Answer 4

Here I am trying to convert a date to UTC and then converting same UTC date as new date. But the issue is that I am not getting same date which I passed.

All Date objects use a single UTC time value, so they are all inherently UTC and there is no need to "convert" them to UTC.

var myDate = '11/2/2015';
var myDateObj = new Date(myDate);
console.log('my Date is \n' + myDateObj);

You shouldn't use the Date constructor (or Date.parse) to parse strings, write a small function or use a library (e.g. moment.js, fecha.js).

The following (replacing getDay with getDate):

var tempDate = Date.UTC(myDateObj.getFullYear(),
                        myDateObj.getMonth(),
                        myDateObj.getDate());

is just a lengthy way of copying a date. Far simpler to use:

var tempDate = new Date(myDateObj);

If you want to get UTC date values, use UTC methods such as myDateObj.getUTCHours, myDateObj.getUTCMinutes, etc.

If you want to get the UTC date and time, use toISOString which returns values with offset 0000:

// Create a Date for 2 November, 2016
var date = new Date(2016,10,2);

// Copy it
var dateCopy = new Date(date);

// Show local date and time
console.log('Local date and time:\n' + dateCopy.toString());

// Show UTC date and time
console.log('UTC date and time  :\n' + dateCopy.toISOString());

// Show UTC Date only
console.log('UTC date only      :\n' + dateCopy.toISOString().substr(0,10));