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/
World Vexillology Day commemorates the debut of Flag Bulletin (October 1961), the world’s first periodical dedicated solely to vexillology.
There is no special flag for this day – just go out and fly flags!
UK Government guidelines state that the Union Flag should be flown on Remembrance Sunday (the second Sunday in November).
https://www.gov.uk/guidance/designated-days-for-union-flag-flying
Scottish government guidance also lists Remembrance Sunday as a flag flying day.
The Union Flag is specified.
https://www.gov.scot/publications/flag-flying-on-government-buildings/
The Royal British Legion recommends flying the Union Flag on Remembrance Day (11 November) and Remembrance Sunday.
https://support.britishlegion.org.uk/app/answers/detail/a_id/263/~/remembrance-faqs
The flag should not be flown at half mast on either day.