Fajr and isha timings

What is the degree we should use for Fajr and Isha salat in Melbourne? For a reference guide, please have a look at what different regions in the world use:
 
http://www.islamicfinder.org/HelpPrayCal.html
 
Last year in October or so, _________  from _________ changed the timings for summer for Isha based on a different calculation to what the calendar is printed.
 
I am quite confused and like to understand this topic a bit more because this not only affects the Isha prayer but it also affects the start time of Fajr payer and thus impact the timings for Sahur (Sehri) for fasting as well.
 
Please advise. Jazakallahu khairan.

In the Name of Allah, the Most Gracious, the Most Merciful.

Isha salat time:

There are two views regarding the starting time of Isha prayer:

1. Upon the disappearance of red twilight (shafaq ahmar) from the horizon. This is the more correct view and the view on which fatwa is given.
2. Upon the disappearance of white twilight (shafaq abyad) from the horizon. This is the more precautionary view.

 
(Note that the disappearance of red twilight takes place before the disappearance of white twilight.)

Hence, although it is permissible to offer Isha salat upon the disappearance of red twilight from the horizon, it is better and more precautionary to offer it after the disappearance of white twilight from the horizon.

Regarding the position of the sun at the time of the disappearance of red twilight and white twilight from the horizon, there are two views among the scholars of the Indo-Pak subcontinent:

1. Red twilight disappears from the horizon when the centre of the sun is 15 degrees below the horizon; and white twilight disappears from the horizon when the centre of the sun is 18 degrees below the horizon. This is the view of the majority of scholars of the Indo-Pak subcontinent.
2. Red twilight disappears from the horizon when the centre of the sun is 12 degrees below the horizon; and white twilight disappears from the horizon when the centre of the sun is 15 degrees below the horizon. This is the view of some scholars of the Indo-Pak subcontinent, such as Mufti Rasheed Ahmad Ludhyanawi (R.A.).

Since salat is a fundamental obligation of every Muslim, one must take all precautions to ensure he/she offers his/her salat correctly and in the correct time. Therefore, taking into consideration the abovementioned views, the following precautionary measures are suggested:

• One should never delay his Maghrib salat to the extent that the sun is 12 degrees below the horizon, as according to the second view mentioned above, this is when the time of Isha salat starts (and the time of Maghrib salat ends). However, one should not offer his Isha salat at this time.
• It is best to offer Isha salat when the sun is 18 degrees below the horizon, as then one’s salat will be valid according to all the scholars.
• If one offers his Isha salat when the sun is only 15 degrees below the horizon, even then his salat will be valid according all the scholars, although according to the first view, this will be before the precautionary time. Hence, it is best to only offer one’s isha salat at this earlier time when there will be considerable difficulty in offering it at the later time, such as during summer time (here in Melbourne) when the time of Isha salat is very late.

 
Fajr salat and beginning of fasting time:

The time of Fajr salat starts upon the appearance of true dawn (fajr sadiq) in the horizon. This is also when the time of fasting starts. One must stop eating before this time if he intends to fast.

There are two views among the scholars of the Indo-Pak subcontinent regarding the position of the sun at the time of the appearance of true dawn in the horizon:

1. True dawn appears in the horizon when the centre of the sun is 18 degrees below the horizon. This is the view of the majority of scholars of the Indo-Pak subcontinent.
2. True dawn appears in the horizon when the centre of the sun is 15 degrees below the horizon. This is the view of some scholars of the Indo-Pak subcontinent, such as Mufti Rasheed Ahmad Ludhyanawi (R.A.).

Based on the two views mentioned above, the following precautionary measures are suggested:

• If one intends to fast, he must stop eating before the sun is 18 degrees below the horizon.
• One should not offer his Fajr salat before the sun is 15 degrees below the horizon.

And Allah knows best.

Mufti Faizal Riza
7/5/2012