Qadha Fasts
In the name of Allah, the most Beneficent, the most Merciful.
Answer
It is not necessary to keep the fasts in order. One can keep it whenever he wishes. However, it is preferable to start keeping it as soon as possible. (Ilmul Fiqh p.29 v.3)
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham