Europe Day is celebrated annually on 5 May and 9 May.
The European Union designates 9 May, the anniversary of the Schuman Declaration (1950).
https://european-union.europa.eu/principles-countries-history/symbols/europe-day_en
The Council of Europe designates 5 May, the anniversary of the Council’s founding.
https://www.coe.int/en/web/portal/5-may-europe-day
Europe Day is listed on 9 May as a flag flying day by Scottish government guidance.
The European Flag is specified.
https://www.gov.scot/publications/flag-flying-on-government-buildings/
Neither date is listed as a flag flying day by UK government guidance, although the UK remains a member of the Council of Europe.
https://www.gov.uk/guidance/designated-days-for-union-flag-flying
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/
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
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
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/
The birthday of the Princess Royal 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/
Merchant Navy Day – introduced by the UK government in 2000 – is not listed as a flag flying day by UK Government Guidance.
https://www.gov.uk/guidance/designated-days-for-union-flag-flying
Merchant Navy Day is listed as a flag flying day by Scottish government guidance.
The Red Ensign is specified.
https://www.gov.scot/publications/flag-flying-on-government-buildings/
Merchant Navy Day is also celebrated by the Senedd Cymru.
The Red Ensign is specified.
https://senedd.wales/media/hl5dtuct/foi-574-final-redacted-response-saes.pdf
The Accession Day 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 Accession Day 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/
United Nations Day takes place annually on 24 October, marking the entry into force of the UN Charter (1945).
The UK Government, Scottish Government and Senedd Cymru do not currently list it as a flag flying day.
