when do we fast?

[nerspi]

peace

i was reading about ramadan and i wanted to know when it is and i found out that the ramadan means, the hottest month or scorching month. so apparently we have to fast in the hottest month of the year.

now, my question is,
do i have to fast when the hottest month hits the country i'm living in?
or
do i have to fast when the hottest month hits saudi arabia?

because the qur'an was revealed in the hottest month in makkah
and the hottest month in makkah is july
(that's the month when the sun is right above arabia)

now, the hottest month in australia is january
(that's the month when the sun is right above australia)
so does a person in australia have to fast in january or july?
because january is the hottest month there
but the qur'an was revealed when the hottest month is in arabia

example 1
lets say i take a trip to makkah in july, and the sun is right above me and i can see that this is the hottst month of the year and this is where the prophet lived when he was receiving the qur'an and was told to fast in the hottest month and this was it. the month where the sun is right above him. now i should fast in this month, when the sun is above arabia, makkah.

example 2
lets say i take a trip to somewhere in australia six months later, in january, when the sun is above australia, and i look up and see the sun above me, and i can see that this is the hottest month of the year. but although this is the hottest month, it isn't the one in which the qur'an was being revealed in. that month was six months ago, when the sun was above arabia. now should i fast again, after six months, just because this is the hottest month?

my brother thinks we have to fast in the hottest month based on location,
like if you're in arabia, you fast in july and if you're in australia you fast in january

now, do we fast in the hottest month JUST BECAUSE it is the hottest month,
no matter the location?

or do we fast in the hottest month because the qur'an was revealed then?

i think that we should all fast when the hottest month is in arabia
because the qur'an was started being revealed only in one month
and that was in arabia and it was when it was the hottest there

if i'm wrong, please let me know why

[Alen]

Salam.

We in Slovenia fast when it is the hottest month here.
Australians fast when it's the hottesz month in Australia.
.....

Get it?
Australians can't fast at the same time as me. When i'm having the hottest month in Slovenia, i fast, Australians wait until it's their hottest month.

In short, when i fast, they don't and vice versa.
May The Almighty Allah Most Merciful reward you with Paradise.

Salam.