وَقَضَاءُ رَمَضَانَ إِنْ شَاءَ فَرَّقَهُ، وَإِنْ شَاءَ تَابَعَهُ.
Translation: Ramadan make-up fasts may be performed on separate days or consecutively.
Farraqahu means distributing make-up fasts across separate days, while tābaʿahu means keeping them consecutively. The expression in shāʾa allows both approaches.
Consequently, consecutive performance is not a strict validity condition for ordinary Ramadan make-up. The desirability of prompt completion is a distinct consideration.