Derbyshire Day takes place annually on 22 September.
BBC Radio Derby presenter Andy Whittaker organised a vote, and the chosen date commemorates the first raising of the flag.
Alternative suggestions included: 28 July – Derby, the county town, granted city status; 12 May – the birthday of Florence Nightingale, who spent her early years in the county.
Cumberland Day takes place each year on 24 September.
It marks the anniversary of the baptism of renowned local character John Peel (1776-1854).
Montmouthshire Day takes place each year on 25 September, the feast of Saint Cadoc or Cadog (born c. 497).
Cadoc was the founder of the monastery of Llancarfan, and a pioneer of Celtic Christianity in Wales.
Westmorland Day takes place annually on 29 September.
It marks the date in 1397, when King Richard II created Ralph Neville the first Earl of Westmorland.
A poll at the Westmorland County Show (2013) chose this day.
Other options included: 30 January – birth of Lady Anne Clifford; 30 July – death of Thomas de Strickland; 1 October – battle of Tinghai; 21 October – death of Earl Ralph Neville; 18 December – battle of Clifton (perhaps the last battle on English soil).
Lincolnshire Day takes place annually on 1 October.
It commemorates the Lincolnshire Rising, which began at Louth on 1 October 1536.
The rebels were protesting against the English Reformation and the Dissolution of the Monasteries.
Northamptonshire Day takes place annually on 25 October, the feast of St Crispin.
St Crispin is the patron saint of shoemakers, cobblers and leather workers – an important industry in the county.
The vote that selected the county day included several other options: 5 January – death of Philippa of Lancaster (1430), queen of Denmark, Norway and Sweden; 26 February – radar first demonstrated in Upper Stowe; 31 May – death of Waltheof (1076), 1st Earl of Northampton and last of the Anglo-Saxon earls; 28 July – battle of Talavera (1809), battle honour of the Northamptonshire Regiment, which gained the nickname ‘The Heroes of Talavera’.
Essex Day takes place annually on 26 October, the feast of St Cedd.
Cedd (c.620–64) was an Anglo-Saxon monk and bishop who was an evangelist among the East Saxons.
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/
Lancashire Day has taken place annually on 27 November since 1996.
It commemorates the day when Lancashire first sent representatives to Parliament, the Model Parliament of King Edward I (1295).
