Question: as the topic suggest - I'm looking to get a date when all I have is **year** (ex. 2014), **week number** (ex. 47) and **day number** within that week (ex. 3 - which would be Wednesday). 

I've seen some similar questions the other way around, but reverse-engineering answers didn't provide any successful results.

Any ideas?

Answer: 
I would highly recommend you to use the [moment.js](http://momentjs.com/) library. This is a complete date manipulation library.

Your problem would be solved by this `moment().year(2014).week(47).day(3).toDate();`
```js
function getDatebyWeek(year, week, day) {

  var d = {
    year: year,
    month: 0,
    day: 1
  };

  var date = new Date(d.year, d.month, d.day);
  var weekCount = 0;
  var month = 1;

  var done = false;

  while (weekCount < week) {

    while (date.getMonth() < month) {

      if (d.day % 7 === 0) {
        weekCount++;
      }

      d.day++;
      date.setDate(d.day);

      if (weekCount === week) {
        done = true;
        break;
      }

    }

    if (done) {
      break;
    }

    month++;

    d.month = month - 1;
    d.day = 1;

    date.setMonth(d.month);
    date.setDate(d.day);

  }

  if (day <= d.day && day >= (d.day - 7)) {
    return new Date(d.year, d.month - 1, day);
  } else {
    throw new Error('The day you entered is not in week ' + week);
  }

}

var wk = getDatebyWeek(2014, 47, 22);

document.write(wk.toString());
```

I wrote this really ugly function in case you have something against moment.js :)