Is it permissible for a resident in non-Islamic countries to fast and break their fast according to the timing of the Kingdom of Saudi Arabia?

The adoption of a particular country's sighting for the beginning or end of Ramadan is due to scholarly اختلاف (disagreement). The majority of scholars hold that the sighting is for all Muslims, based on the hadith: "When you see it, fast; and when you see it, break your fast." However, Imam Al-Shafi'i and a group of scholars are of the opinion that there are differences in moonrises (matali'), and that the address in the hadith is for those in whose locality the crescent moon is sighted. This latter opinion is the more preponderant (rajih), and it is based on its being inconsistent with reason (ma'qul) regarding the difference in timings, and with tradition (manqul) through the hadith of Kurayb and Ibn Abbas (may Allah be pleased with them both), where the people of Al-Sham sighted the crescent moon on Thursday night, while the people of Al-Madinah sighted it on Friday night. Ibn Abbas said: "This is how the Messenger of Allah (peace be upon him) commanded us." And Al-Tirmidhi stated that the practice among scholars based on this hadith is that each country has its own sighting.