Bismillah. *Sunday 19th August 2012 is a sensible date for Eid al-Fitr 1433 for the whole world.*
Please refer to the Moonwatch data (http://astro.ukho.gov.uk/moonwatch/nextnewmoon.html), that shows:
Friday 17/8: Conjunction and astronomical new moon around 15.54 UT (GMT) – no crescent moon is visible anywhere on earth that night, except possibly in the Southern Pacific, very close to the solar date-line.
Saturday 18/8: The crescent moon is visible throughout the Southern Hemisphere, plus a few places north of the Equator, but not in Asia, the Middle East, North Africa or Europe.
Sunday 19/8: The crescent moon is easily visible throughout the whole world, including the UK.
Sunday 19th August 2012 is a sensible date for Eid al-Fitr 1433 for the whole world: there is expected to be a high degree of agreement on this, as has happened in previous years. (Those who began Ramadan on Fri/Sat 20/21 July will complete 30/29 days of fasting and celebrate Eid together.)
For those following local sightings, Monday 20th August 2012 would be Eid al-Fitr 1433 in the UK.
May Allah bless us all during the remainder of Ramadan and on the glorious day of Eid al-Fitr (the Festival of Breaking the Fast).
Dr. Usama Hasan,
Senior Researcher in Islamic Studies at Quilliam & Fellow of the Royal Astronomical Society
15th August 2012 / 26th Ramadan 1433