I'm making an app that allows me to keep track of my income/spendings in Android. I want the app to be able to show me incomes and spendings over a certain timespan. 

What I've got so far is this

```
 public void buildArray (String num, String kat, String titel) {
        Set<String> mySet = new HashSet<String>();
        mySet.add(num);
        mySet.add(kat);
        mySet.add(titel);

        saveData(mySet);
    }

    public void saveData (Set<String> setName) {
        SharedPreferences sp = this.getActivity().getSharedPreferences("Utgifter", Context.MODE_PRIVATE);
        SharedPreferences.Editor edit = sp.edit();

        Date date = new Date();

        edit.putStringSet(String.valueOf(date), setName);
        edit.commit();

    }

```

For every entry the user makes I want to store four values. The amount, the category and a title for the entry, and the current time as the key.

My question is how do I read stringsets from the SharedPreferences and is using the date as a key a good idea? Is there anyway to loop through all the saved values and read the ones in a certain time interval?

Thanks!