Islamic Calendar

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:

CE / AD	AH	First day	Last day
2003	1424	26 October	24 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	1 September	30 September
2009	1430	22 August	19 September
2010	1431	11 August	9 September
2011	1432	1 August	29 August
2012	1433	20 July	18 August
2013	1434	10 July	7 August
2014	1435	28 June	27 July
2015	1436	18 June	16 July
2016	1437	6 June	5 July
2017	1438	27 May	25 June
All of the Ramadan dates between 2014 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. Astronomical projections that approximate the start of Ramadan are available.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.