When did the Messenger of Allah, may Allah bless him and grant him peace, fast six days of Shawwal?

Fasting the six days of Shawwal is a confirmed Sunnah, due to the Prophet's (peace be upon him) saying: "Whoever fasts Ramadan then follows it with six days from Shawwal, it is as if he has fasted the entire year." There is no mention in the Sunnah that clarifies how the Prophet (peace be upon him) fasted these days, nor anything indicating whether he fasted them or not. The majority of scholars view it as desirable to fast them consecutively after Ramadan.