- Imbolc / Candlemas : February 1st/ 2nd
- Spring Equinox : March 20th/ 21st
- Beltane / May Eve : April 30th / May 1st
- Midsummer : June 20th/ 21st
- Lammas/ Lughnasadh : July 31st/ August 1st
- Autumn Equinox : September 22nd/ 23rd
- Samhain / Halloween October 31st/ November 1st
- Yule : December 21st/ 22nd
- Samhuinn : October 31-November 1
- Winter Solstice (Alban Arthan or Alban Arthuan): December 21-22
- Imbolc : February 1-2
- Vernal Equinox (Alban Eiler or Alban Eilir): March 20-21
- Beltaine : April 30-May 1
- Summer Solstice (Alban Heruin or Alban Hefin): June 21-22
- Lughnasada : July 31-August 1
- Autumn Equinox (Alban Elued or Alban Elfed): September 21-22
Different Heathen communities and individuals celebrate different cycles of seasonal holidays based on their cultural affiliations, local traditions, and relationships with particular gods. There is no fixed calendar of Heathen festival dates. The three Heathen festivals most commonly
celebrated in the UK are Winter Nights - usually celebrated in October or November, Yule - a twelve day festival that begins around the time of the winter solstice, and a festival for the Anglo-Saxon goddess Eostre in the spring.
Religio Romana festivals
There are loads of these; and different practitioners seem to celebrate different ones.
One of PFA's members, Aereaus from Denmark, has a blog with details of some lesser-known Pagan festivals. It's called the Pagan Left, and includes details of ancient Roman festivals.