January

1st - New Year's Day, Hogmanay, 7th Day of Christmas
2nd - 8th Day of Christmas, 2nd Day of Hogmanay
3rd - Quadrantids, 9th Day of Christmas
4th - 10th Day of Christmas
5th - Twelfth Night, Old Christmas Eve, 11th Day of Christmas
6th - Epiphany, Old Christmas Day, 12th Day of Christmas
7th - Distaff Day
13th - St. Knut's Day
14th - Festum Asinorum / Fête de L'âne
15th - Martin Luther King, Jr. Day
18th - Winnie The Pooh Day
25th - Burns Night, Diwrnod Santes Dwynwen / St. Dwynwen's Day
28th - Feast of St. Thomas Aquinas

February

1st - Sometimes noted as Imbolc
2nd - Imbolc, Chandeleur / Jour de Crêpe
12th - Darwin Day
28th - Kalevala Day / Day of Finnish Culture

March

1st - St. David's Day
5th - St Piran's Day
12th - Grækarismessa / Mass of St. Gregor
13th - Uranus Day, Pluto Planet Day
15th - Ides of March
17th - St. Patrick's Day
20th - Vernal equinox (approx.), Feast of St. Cuthbert
21st - International Astrology Day, Vernal equinox (tradit.)
25th - Lady Day

April

1st - Skepticism Day
6th - Old Lady Day, Tartan Day
22nd - Shakespeare's birthday?, Earth Day, Lyrids
23rd - St. George's Day, Shakespeare's birthday?
30th - Walpurgis Night, Beltane Eve

May

1st - May Day, Beltane
4th - Eta Aquarids
5th - Europe Day (1)
8th - VE Day
9th - Europe Day (2)
12th - International Nurses Day
13th - Abbotsbury Garland Day
15th - Whitsunday (Scotland)
18th - International Museum Day
19th - Lesser Phi Day
24th - Aldersgate Day in Methodism
29th - Oak Apple Day / Shick-Shack Day / Arbour Day
30th - Feast of Joan of Arc
31st - Lady Godiva procession

June

6th - D-Day
7th - Arietids
8th - World Ocean Day
12th - Trooping the Colour
16th - Bloomsday
17th - St. Botolph's Day
19th - Juneteenth
21st - Summer solstice (approx.)
23rd - Midsummer's Eve, Feast of St. John the Baptist
24th - Midsummer Day
27th - Veterans' Day, Siebenschläfertag

July

3rd - Start of the Dog Days
5th - Tynwald Day / Laa Tinvaal
13th - John Dee's birthday
22nd - Ratcatcher's Day
25th - Ebernoe Horn Fair
28th - Southern Delta Aquarids

August

1st - Lughnasadh, Lammas, Yorkshire Day, National Farming and Agriculture Day
7th - Summerhalf?
12th - Perseids
13th - Greater Phi Day
15th - VJ Day, Feast day of the Assumption of Mary
18th - International Lighthouse Day
24th - Bartholomew Fair
28th - Feast day of Saint Augustine of Hippo

September

8th - International Literacy Day, Rhodri Day?
15th - Battle of Britain commemeration, International Day of Democracy
19th - International Talk Like a Pirate Day
24th - Our Lady of Walsingham Day
26th - European Day of Languages
29th - Michaelmas
30th - Nietzschean New Year

October

4th - World Animal Day
9th - Giacobinids / Draconids
10th - Old Michelmas
12th - Sutton Bridge jewels day
17th - International Day for the Eradication of Poverty
21st - Trafalgar Day, Apple Day, Orionids
31st - Bartholomew Fair play day, Reformation Day

November

1st - Samhain, All Saints' Day
2nd - All Souls' Day
5th - Guy Fawkes Night
11th - Martinmas, Remembrance Day, Armistice Day
12th - Taurids
17th - Leonids
19th - World Toilet Day
20th - Wedding day of Queen Elizabeth II
24th - Evolution Day
30th - St Andrew's Day

December

1st - Start of Advent (coll.)
5th - Krampus
6th - St. Nicholas Day
10th - Human Rights Day, Nobel Prize ceremony
13th - St. Lucy's Day, Geminids
15th - Zamenhof Day
21st - Yule (approx.)
22nd - Ursids
24th - Christmas Eve
25th - Christmas Day
26th - Boxing Day, 1st Day of Christmas
27th - 2nd Day of Christmas
28th - 3rd Day of Christmas
29th - 4th Day of Christmas
30th - 5th Day of Christmas
31st - New Year's Eve, Hogmanay, 6th Day of Christmas