How to get first date and last date of the week from week number and year?
Try this:
var year = 2012;
var week = 2;
var d = new Date("Jan 01, " + year + " 01:00:00");
var w = d.getTime() + 604800000 * (week - 1);
var n1 = new Date(w);
var n2 = new Date(w + 518400000)
console.log(n1);
console.log(n2);n1 contains the first day of the week
n2 contains the last day of the week
As for the constants:
604800000 is one week in milliseconds
518400000 is six days
A little change to @bardiir 's answer, if the first day of the year is not Sunday(or Monday) that result is not correct. You should minus the number of the first day.
Changed code
firstDay = new Date(2015, 0, 1).getDay();
console.log(firstDay);
var year = 2015;
var week = 67;
var d = new Date("Jan 01, " + year + " 01:00:00");
var w = d.getTime() - (3600000 * 24 * (firstDay - 1)) + 604800000 * (week - 1)
var n1 = new Date(w);
var n2 = new Date(w + 518400000)
console.log(n1);
console.log(n2);if you wish the first is Sunday, change (firstDay-1) to firstDay