how many weeks from now to sometime

nWeekFromNow

function nWeekFromNow(ts) {
  var now = new Date();
  now.setHours(0);
  now.setMinutes(0);
  now.setSeconds(0);
  now.setMilliseconds(0);

  var nowTS = now.getTime();
  var nowDay = now.getDay() || 7;
  var startTS = nowTS - (nowDay - 1) * 24 * 60 * 60 * 1000;

  var nWeek = Math.ceil( Math.abs(startTS - ts) / 1000 / 60 / 60 / 24 / 7 );
  
  return ts >= startTS ? 0 : nWeek;
}