Quick notes about the patronesses and which holidays would be theirs.
Using the WotY as a basic template since so few pony holidays are known, but here are the translations/correspondences Ive got so far-
Yule: Hearth’s Warming
Ostara: Winter Wrap Up
Midsummer: Summer Sun
*Lughnasadh: Summer Harvest Parade
Mabon: Running of the Leaves
Samhain: Nightmare Night
Nothing for Imbolc, Beltane, or Lughnasadh* yet. Maybe next season…
*Edit: After another rewatch, I was reminded of the Summer Harvest Parade, which I think would correspond to Lammas/Lughnasadh, being the “first harvest” and all! So I added it above.