Is it permissible to change the intention of a make-up fast (qada') to the intention of fasting six days of Shawwal on the same day after noon, upon remembering the completion of the make-up days?

It is understood from the words of some scholars that there is no objection to considering the fasting of the Day of Ashura as part of the six days of Shawwal, based on the principle that a supererogatory fast—even if it is time-specific—is valid with a general intention and does not require specific designation. As mentioned in "Al-Iqna'" and "Ghayat al-Bayan," fasting on days for which fasting is emphasized is directed towards them, and even if one intends something else, the reward for those days is also obtained.