Reference: Fataawa Ramadhaan v2 p657 no.661
ad-Durur as-Sunniyah fil-Ajwibah an-Najdiyah v5 p360
Question: Is continuity (i.e. fasting all the required days consecutively) obligatory in making up the fasts of Ramadhaan?
Response: As for making up the fasts of Ramadhaan, then continuity [in making them up] is not obligatory.

