International Workers’ Memorial Day is a day of remembrance and action for workers killed, disabled, injured, or made unwell by their work.
It is an official flag flying day only in Scotland, not in the rest of the UK.
The saltire(s) should be hoisted right up and then lowered to half-mast for the day.
https://www.gov.scot/publications/flag-flying-on-government-buildings/
Staffordshire Day commemorates the foundation date of Josiah Wedgwood and Sons (1759).
The date was selected by public vote from a list that includes: 5 July – discovery of the Staffordshire Hoard (2009); 6 September – the future King Charles II hid in an oak tree in South Staffordshire (1651); 18 September – Doctor Samuel Johnson born in Lichfield (1709); 27 September – James Brindley, renowned engineer and resident of Leek, died (1772)
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/
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
Somerset Day was selected by public vote from a shortlist that includes: 19 May – Feast of St Dunstan; 6 July – Battle of Sedgemoor.
The battle of Albuera (1811) took place during the Peninsular War, when Anglo-Portuguese forces defeated the French.
The 57th (West Middlesex) Foot suffered very heavy casualties during the battle and later celebrated the anniversary as a regimental day.
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 Aldhelm (639–709) was Abbot of Malmesbury and Bishop of Sherborne.
St Augustine of Canterbury (d.604) became the first Archbishop of Canterbury in 597.
The Church of England considers him to be one of its founding fathers.
Northumberland Day takes place annually on the last Sunday in May.
