Shetland Day takes place annually on 21 June.
Shetland Islands Council chose this date simply because it it the longest day of the year.
Suffolk Day takes place annually on 21 June.
Former BBC radio presenter Mark Murphy created the event in 2016.
It has since become a staple in the Suffolk calendar, hosted by towns across the county.
Mercia Day takes place annually on 22 June, the feast of St Alban.
St Alban is the first recorded British Christian martyr, by tradition beheaded in Verulamium (modern St Albans) during the third or fourth centuries.
The British Virgin Islands celebrate Territory Day annually on 1 July.
On this date in 1956 the islands became a separate British Overseas Territory.
The Isle of Man celebrates Tynwald Day (Manx: Laa Tinvaal) annually on 5 July, unless this date falls on a Saturday or Sunday.
In this case Tynwald Day takes place on the following Monday.
Black Country Day celebrates the installation of the first practical steam engine by Thomas Newcomen (1712).
Hampshire Day takes place annually on 15 July, the Feast Day of St Swithun.
St Swithun was Bishop of Winchester (852–63) and subsequently patron saint of Winchester Cathedral.
The Birthday of HM The Queen is listed as a flag flying day by UK government guidance.
The Union Flag is specified.
https://www.gov.uk/guidance/designated-days-for-union-flag-flying
The Birthday of HM The Queen is also listed as a flag flying day by Scottish government guidance.
The Scottish Saltire is specified.
https://www.gov.scot/publications/flag-flying-on-government-buildings/
Historic County Flags Day takes place annually on 23 July, giving an opportunity for individuals and organisations to show pride in their historic county.
The date commemorates the creation of the Devon Flag (2002), triggering the movement to design a modern flag for each of the UK’s historic counties.
Since 2019 (not 2020) the flags have flown together in Parliament Square, London.
Buckinghamshire Day marks the origin of the Paralympic Games.
On the opening day of the London Olympics (1948), Stoke Mandeville Hospital hosted the first event ever organised for disabled athletes alongside an Olympic Games.
The Stoke Mandeville Games later became the Paralympic Games, which first took place in Rome (1960).