Shawwal ke Chhe Roze

One page, and it does three things in order.

It states the objection: some have said the six fasts of Shawwal are not established. He answers that this is not correct: they are established, and great merit has been reported for them.

It gives the evidence: the hadith of Abū Ayyūb al-Anṣārī, that the Messenger of Allah ﷺ said whoever fasts Ramadan and then follows it with six from Shawwal, it is as though he fasted the whole year, with both references printed, Muslim and Tirmidhī, each with its chapter and number.

And then, in the last three lines, it sets a limit in the other direction, which is why the piece is worth having rather than merely being a citation:

The rule is that if a thing is established in a hadith then it is at the least a sunnah. But exceeding its bounds and turning it into a custom and a convention is not correct, and making it an occasion for feasting is not correct.

Signed Samiruddin Qasmi. The related question of when Ramadan itself begins and ends is Hisab par Ramadan Karna.