Eid inshAllah will be on either Saturday 18th of August or Sunday 19th of August.
Here are the prayer times of the different mosques in Brighton:
Al-Medinah Mosque: 8:30am and 10am
Al-Quds Mosque: 9am
Shahjalal Mosque: 8:30am and 9:30am
According to the Central Mosque of London the Zakat Al Fitr is between £3 and £3.50.