Is it a condition to make the intention for fasting six days of Shawwal at night, and if one makes the intention during the day, is the fast valid or not?

The questioner : May Allah reward the honorableThe Shaykh : Is it a condition to make the intention for fasting the six days of Shawwal at night, meaning, is it permissible if a person wakes up in the late morning on a day of Shawwal and has not eaten anything, does this day count as one of the six days of Shawwal, or is it necessary to make the intention from the night?

The Shaykh : Yes, fasting the six days of Shawwal cannot be realized unless one intends to fast each day before the dawn breaks. If he does not intend until after the dawn breaks, it is not true that he fasted the six days of Shawwal. I give an example for this: on the first day of the six, he did not intend to fast. When the call to the midday prayer was made, he intended to fast, considering it one of the six days, and then he completed it. How many days remain for him?
The student: ...

The Shaykh : No, five days. He fasted the remaining five days. Do we say that this man fasted six days or five and a half days? Yes.
The student: ...

The Shaykh : Five and a half days. The Messenger (peace and blessings be upon him) said: And this person has not fasted except five and a half days, but the reward for fasting that day is written for him, except that it is not counted among the six. So we say: the fast that you intended at the time of the midday prayer is valid, and you are rewarded for it from the beginning of the intention, but it is not counted for you among the six, because the six must be complete days. Yes.