January is month 0. December is month 11. So this should work:

var d = new Date(2016, 11, 17, 0, 0, 0, 0);

Also, you can just simply do:

var d = new Date(2016, 11, 17);

const dateObj = new Date();
const month   = dateObj.getUTCMonth() + 1; // months from 1-12
const day     = dateObj.getUTCDate();
const year    = dateObj.getUTCFullYear();

const newDate = year + "/" + month + "/" + day;

// Using template literals:
const newDate = `${year}/${month}/${day}`;

// Using padded values, so that 2023/1/7 becomes 2023/01/07
const pMonth        = month.toString().padStart(2,"0");
const pDay          = day.toString().padStart(2,"0");
const newPaddedDate = `${year}/${pMonth}/${pDay}`;

or you can set new date and give the above values

According to the documentation, you can use date.getFullYear() to get the year in YYYY format and date.getMonth() to get the month.

An example:

let list = document.getElementById('test');
let date = new Date(2008, 4, 15);


// year
let yearNode = document.createElement("li");
yearNode.appendChild(document.createTextNode(date.getFullYear()));

list.appendChild(yearNode)

// year + month

let yearMonthNode = document.createElement("li");
yearMonthNode.appendChild(document.createTextNode(date.getFullYear() + " " + date.getMonth()))

list.appendChild(yearMonthNode)

<ul id="test">

</ul>