I am writing a program where I need to find same dates...

I currently store the dates on different lists for day and month and then `zip` them to a date list... so the date list might look something like this:

```
[(2,4),(4,18),(10,7)]

```

My problem is I need to extract the duplicate tuples to another list not just eliminate them with some `set()` or so.

If my date list gets `[(2,3),(2,3),(4,8)]` I need to get `(2,3)` to a new list.

Alternatively I could form the date list into a `dictionary` and then piece it again in items but I am asking if there is a simpler way. Any suggestions?