如何从星期数获取JavaScript日期？

Question

我如何在javascript（或jquery）中从星期数和年份中获取一周中第一天的日期？

例如：2013年第30周

提前致谢 ！

Answer 1

var d = new Date(year, 0, 1);
var days = ['sun', 'mon', 'tue', 'wed', 'thu', 'fri', 'sat'];

d.setDate(d.getDate() + (week * 7));

console.log(days[d.getDay()]);

尝试这个

Answer 2

function getDateByWeek( weeks, year ) {
   var date = new Date(year, 0, 1);
   var dayNum = d.getDay();
   var requiredDate = --weeks * 7;
   // If 1 Jan is Friday to Sunday, go to next week 
   if (((dayNum!=0) || dayNum > 4)) {
       requiredDate += 7;
    }
  // Add required number of days
   d.setDate(1 - d.getDay() + ++requiredDate );
   return date;
 }