I have been doing as much research as possible on the Pleiades themselves and their various worldwide folklore and I have also been trying to connect to my own spiritual gnosis on the topic. I wrote previously on some of my basic findings about the Pleiades, so I won't rehash that here; my more recent efforts have been on trying to work out a modern schedule based on the Pleiadean cycle. I had already uncovered 4: the conjunction with the sun which occurs around old Bealtaine (mid-May), the heliacal rising six weeks later in June (theoretically around the solstice?), the acronychal rising (around the autumnal equinox), and the culmination (Nov. 21). I feel like there are at least two more significant Pleiadean dates, probably the heliacal setting and acronycal setting, but so far I haven't had much luck finding out when those events occur. I'm still working on it and of course actually following the stars for a year or several will help with this. Being me I'll probably add in a 7th holiday just because I like the number. Right now I think that the spring equinox is also an important time, if only because the Pleiades used to align there for the conjunction and that was a very sacred time across many cultures.
The cycle as I've been able to piece it together so far is based on rough information about when the Pleiades is at the highest point of the sky. This occurs at midnight on November 21st, and then progresses backwards by 4 hours every two months, so that by late January it is at its highest point (although slightly south of midsky) at 8pm, then at its highest point in March at 4 pm, and so on. This is inline with the conjunction in May/June when the Pleiades would be at its highest point in the sky at noon. Obviously this is only the very beginning of sorting out this cycle and more importantly of figuring out the key ritual points to acknowledge, but it is a beginning.
My personal preference right now is to tentatively call these dates:
The conjunction around Mid-May: The Darkening
The heliacal rising in June: The Return of the Queens (or just the Returning)
The acronychal rising in late September: The Way-Opening
The culmination in late November: The Rade
I have some tentative story around these, I wouldn't call it mythology of course because it's new but stories seems accurate. I think its important though that these not just be new dates for the holidays we already have, exactly, but rather that we acknowledge these are both old and new. Yes I do believe that the Pleiades were celebrated as the original markers for certain holy days - and world mythology supports this of course - but because of the drift in timing we can't just go back to that. The conjunction isn't in late March anymore its in May; the heliacal rising isn't in May its in June. That makes a significant difference when these aren't just cold dates but also living traditions. We have to find the threads of the old and the hints of the significance this may have had for us in our own forms of historic paganism, and even back before into the roots of the neolithic and bronze ages, and then work those traces into a viable modern system.
When I see the Pleiades it looks to me like a blue bonfire burning in the sky and I can imagine it easily as a gathering place of celestial Queens, of Fairy Queens, of seven Divine Sisters. When the star-fire that is the Pleiades disappears from the night sky the Queens have parted ways and left their Courts. Maybe they are travelling on earth. Maybe they are searching for something. Maybe they are sowing change or strife or beginnings or endings. They each have their own agendas. When the constellation returns to the horizon the Queens have returned, gathered together again to exchange news and share stories. When the stars rise at sunset it represents the Opening of the Way Between Worlds, when the dead and Good Folk and Others have more freedom to move within our world. The culmination is when the Fairy Rades ride out, and the Wild Hunt is especially active.
I suspect that the time in late december and early January as well as around the spring equinox are also very important but I haven't quite gotten the pieces together yet for those. My gut tells me that the dec/january period represents a point of high activity for the Otherworld and so perhaps another key Pleiadean date and that the spring equinox may connect to the new year*. I am planning to celebrate the culmination this year with a ritual and with a symbolic feast the following day.
As to the Queens? There is a lot of lore around the Pleiades that a person can easily use and much of it relates the 7 stars to women. For myself I have come to see them as 7 Fairy Queens because that is what makes sense to me. I may have names for them but I prefer to use titles: Queen of the Greenwood, Queen of the Wind, Queen of the Wave, Queen of Winter, Queen of Flame, Queen of Horns, and the Crane Queen.
I'll post more later and I'll share about the ritual I do in November if people are interested.
*the spring equinox was viewed as the date of the new year until the 18th century in the United States and parts of Europe, and I'm really chewing on that right now. https://www.bostonglobe.com/ideas/2014/03/22/march-happy-colonial-new-year/L0MrkQc47SiUu1OHVJt1lI/story.html
Horne, J., (2018) Pleiades Sparkle On Winter Nights https://www.fayobserver.com/49a7eb0c-4d2a-5c97-afc9-b129ee59ba3b.html
Gibson, S., (2018) The Pleiades https://www.naic.edu/~gibson/pleiades/
Kramer, J., (2004) A Starry Calendar Part 1 https://www.lcas-astronomy.org/articles/display.php?filename=a_starry_calendar&category=observing