The Modern JS Tutorial: Date and Time: Which day of month was many days ago

	function getDateAgo(date, days) {
	const copiedDate = new Date(date);
	copiedDate.setDate(copiedDate.getDate() - days);
	return copiedDate;
	}
	let date = new Date(2015, 0, 2);
	console.log( getDateAgo(date, 1).getDate() ); // 1, (1 Jan 2015)
	console.log( getDateAgo(date, 2).getDate() ); // 31, (31 Dec 2014)
	console.log( getDateAgo(date, 365).getDate() ); // 2, (2 Jan 2014)
	console.log( getDateAgo(date, 1) );
	console.log( getDateAgo(date, 2) );
	console.log( getDateAgo(date, 365) );

view raw jst_dateAndTime_4_whichDayOfMonthWasManyDaysAgo.js hosted with ❤ by GitHub