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.
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.
The 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 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/
St David’s Day is Wales’ national day.
The Senedd Cymru flies the Welsh national flag – Y Ddraig Goch (The Red Dragon) – all year round.
On St David’s Day it also flies the flag of St David (below).
https://senedd.wales/media/hl5dtuct/foi-574-final-redacted-response-saes.pdf
St David’s Day is also listed as a flag flying day (for Wales only) by UK government guidance.
The Union Flag is specified.
https://www.gov.uk/guidance/designated-days-for-union-flag-flying
Commonwealth Day is the second Monday in March.
The UK government states that the Union Flag should be flown.
https://www.gov.uk/guidance/designated-days-for-union-flag-flying
The Scottish government states that the Commonwealth flag should be flown.
https://www.gov.scot/publications/flag-flying-on-government-buildings/
The Senedd Cymru states that the Commonwealth flag should be flown.
https://senedd.wales/media/hl5dtuct/foi-574-final-redacted-response-saes.pdf
St Patrick’s Day is listed as a flag flying day (for Northern Ireland only) by UK government guidance.
The Union Flag is specified.
https://www.gov.uk/guidance/designated-days-for-union-flag-flying
There is no official, current pan-Ireland or Northern Ireland flag that may be used to mark St Patrick’s Day.
St Patrick’s Saltire is one of several possible alternatives.
The Wedding 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
St George’s Day is England’s national day – St George was named as England’s principal patron saint in 1416.
St George’s Day is listed as a flag flying day (for England only) by UK government guidance.
https://www.gov.uk/guidance/designated-days-for-union-flag-flying
The Union Flag is specified.
Europe Day is celebrated annually on 5 May and 9 May.
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
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
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
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/
The Coronation 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 Coronation 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/