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();`
From : [Getting first date in week given a year,weeknumber and day number in javascript](https://stackoverflow.com/questions/11890632/getting-first-date-in-week-given-a-year-weeknumber-and-day-number-in-javascript)

The answer to OP would be (if dayNumber starts from 1 (Monday) - to 7 (Sunday)):

```js
function getWeekDate(year, weekNumber, dayNumber) {
  var date = new Date(year, 0, 10, 0, 0, 0),
      day = new Date(year, 0, 4, 0, 0, 0),
      month = day.getTime() - date.getDay() * 86400000;
  return new Date(month + ((weekNumber - 1) * 7 + (dayNumber - 1)) * 86400000);
};

alert(getWeekDate(2014, 47, 3));
```