Bismillah. Please refer to http://www.crescentmoonwatch.org, “next new moon” tab.
* A sensible Ramadan start date for the whole world is Saturday 21st July 2012. *
19th July: Conjunction (astronomical new moon or birth of the moon) around 0424 UT. New crescent moon (hilal) visible only from the Southern Pacific Ocean.
20th July: hilal visible throughout Australasia, Asia, Africa, Southern Europe (although not the UK) and the Americas.
21st July: hilal visible throughout the world, including the UK.
Therefore, based on crescent-sighting and instant telecommunication (refer to Ibn Taymiyyah’s fatwas about the relevance of knowledge and communication in moonsighting, available at https://unity1.wordpress.com), 21st July is a sensible Ramadan start date for the whole world, God-willing.
May God accept the fasting, prayers, charity and worship of all His servants.
Senior Researcher (Islamic Studies), Quilliam & Fellow, Royal Astronomical Society
9th July 2012