The holy month of Ramadan comes to an end with Eid al-Fitr celebrations, but exactly when depends on where you are in the world. The exact end of Ramadan, and the start of Shawwal, the 10th month in the Islamic calendar, depends on the sighting of the crescent moon.
In the UK, a new moon is expected was visible on Thursday, April 20, but only under certain weather conditions.
Because the UK doesn't have its own official moon sighting board, the majority of UK Muslims follow Saudi Arabia's moon sighting. The committee sighted the moon on Thursday, April 20, which means that Eid falls today, Friday April 21.