the closest Sunday before given date with JavaScript

Question

I need to know the date for last Sunday for given date in php & javascript

Let\'s have a function give_me_last_Sunday

Answer 1

final code (big thanks to @Thomas & @Rob)

function lastSunday(d) {
  var d = d.replace(/(^\d{4})(\d{2})(\d{2}$)/,'$1/$2/$3');

  d = new Date(d);
  d.setDate(d.getDate() - d.getDay());

  year = d.getFullYear()+'';
  month = d.getMonth()+1+'';
  day = d.getDate()+'';
  if ( month.length == 1 ) month = "0" + month; // Add leading zeros to month and date if required
  if ( day.length == 1 ) day = "0" + day;  

  return year+month+day;
}