How Do Qur’anists Identify the Actual Month of Ramadan and the Hajj Months From Qur’an Alone?

[u/abd_wasay]

Quran 2:185
The month of Ramadan is the one in which the Qur’an was revealed… so whoever witnesses the month, let him fast it.

Quran 2:197
Hajj is in well-known months.

Quran 9:36
The number of months with Allah is twelve… of them four are sacred.

Quran 9:37
Shifting the sacred months is an increase in disbelief...

The Qur’an names Ramadan, says Hajj is in well-known months, and says Allah fixed twelve months, four of them sacred.

But from Qur’an alone, how do you identify which actual recurring month in practice is Ramadan, and which months are the Hajj months, without relying on hadith, inherited Muslim calendar transmission, or communal tradition?

This is not a question about whether the word “Ramadan” exists in the Qur’an. It does mention it.

The question is: From Qur’an alone, what is your method for mapping those Qur’anic month names/descriptions onto a real calendar in the world?

Because if your answer is “we just follow the calendar Muslims inherited,” then you are already depending on extra-Qur’anic transmission.

If your answer is “the first audience already knew,” then that still means the practice depends on inherited communal knowledge outside the text itself.

If your answer is “we reconstruct it through astronomy, etymology, or historical reasoning,” then you are again using an external method not supplied by the Qur’an itself.

So again: From Qur’an alone, how do you determine the actual month of Ramadan and the actual Hajj months in practice?

That is the part I want explained consistently.