from wikipedia
The Islamic calendar is a lunar calendar, and months begin when the first crescent of a new moon is sighted. Since the Islamic lunar calendar year is 11 to 12 days shorter than the solar year and contains no intercalation, Ramadan migrates throughout the seasons. The Islamic day starts after sunset. The actual and estimated start and end dates for Ramadan in 2003–2017 were and are as follows:[2]
| CE / AD | AH | First day | Last day |
|---|---|---|---|
| 2003 | 1424 | 27 October | 25 November |
| 2004 | 1425 | 15 October | 13 November |
| 2005 | 1426 | 4 October | 2 November |
| 2006 | 1427 | 24 September | 23 October |
| 2007 | 1428 | 13 September | 12 October |
| 2008 | 1429 | 01 September | 30 September |
| 2009 | 1430 | 22 August | 20 September |
| 2010 | 1431 | 11 August | 09 September |
| 2011 | 1432 | 01 August | 29 August |
| 2012 | 1433 | 20 July | 18 August |
| 2013 | 1434 | 09 July | 07 August |
| 2014 | 1435 | 28 June | 27 July |
| 2015 | 1436 | 18 June | 16 July |
| 2016 | 1437 | 06 June | 05 July |
| 2017 | 1438 | 27 May | 25 June |
| All of the Ramadan dates between 2013 and 2017 are estimates | |||
Many Muslims insist on the local physical sighting of the moon to mark the beginning of Ramadan, but others use the calculated time of the new moon or the Saudi Arabian declaration to determine the start of the month. Since the new moon is not in the same state at the same time globally, the beginning and ending dates of Ramadan depend on what lunar sightings are received in each respective location. As a result, Ramadan dates vary in different countries, but usually only by a day. This is due to the cycle of the moon. The moon travels the same path all year round and when the moon is seen in the east, it is then seen traveling towards the west. All the countries around the world see the moon within a 24 hour period once spotted by one country in the east.
Each year, Ramadan begins about eleven days earlier than in the previous year.[3] Astronomical projections that approximate the start of Ramadan are available.[4] It takes about 33 years and five days for Ramadan to complete a twelve month move across the yearly calendar. As Ramadan 28 March 1990 to Ramadan 22 March 2023.
