The International Day against Homophobia, Transphobia and Biphobia is an official flag flying day only in Scotland, not in the rest of the UK.
https://www.gov.scot/publications/flag-flying-on-government-buildings/
St Helena’s national day commemorates the island’s discovery in 1502 by Galician navigator João da Nova, then serving the King of Portugal.
Anchoring in the present James Bay, da Nova named the island ‘Santa Helena’ after St Helena of Constantinople, whose feast according to the Orthodox Church falls on 21 May.
Anguilla Day takes place annually on 30 May.
On 30 May 1967 the Anguillans began a revolution that led to independence from the union of St Kitts-Nevis-Anguilla.
Bermuda Day first took place as Empire Day on 24 May 1902.
It continued on that day until 2018, when it moved to the last Friday of May.
It is also known as Heritage Day, celebrating the island’s culture and heritage.
The Falkland Islands celebrate Liberation Day annually on 14 June.
The date commemorates the liberation of the islands from Argentine military occupation in 1982.
The official birthday of HM The King 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 official birthday of HM The King 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/
Autistic Pride Day is an official flag flying day only in Scotland, not in the rest of the UK.
https://www.gov.scot/publications/flag-flying-on-government-buildings/
The birthday of the Duke of Rothesay (Prince of Wales) is 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/
The Birthday of the Prince of Wales is also 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 the Prince of Wales 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
Under his Scottish title (Duke of Rothesay), the Birthday 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/
Armed Forces Day takes place each year on the last Saturday in June.
It is an official flag flying day in Scotland.
https://www.gov.scot/publications/flag-flying-on-government-buildings/
The UK government does not designate it as an official flag flying day in the rest of the UK.
https://www.gov.uk/guidance/designated-days-for-union-flag-flying
However the Senedd Cymru flies the Armed Forces Day flag on 24 June and throughout the preceding week.
https://senedd.wales/media/hl5dtuct/foi-574-final-redacted-response-saes.pdf
