There is an ancient Roman festival called the Nemoralia which was held on either the 13th-15th of August or over the full moon of August. This festival is in honour of Diana Nemorensis. Women would hold a torch procession to Lake Nemi, they would leave Diana various offerings as well as tokens of gratitude and requests for various help especially healing.
Diana was often heavily conflated with Hekate, both being named Trivia – indeed one can see in Diana the beginnings of the modern triple goddess. Hekate is of course a torch bearing Goddess, making this festival peculiarly suited to Her, even without the Diana conflation. Some, including Wikipedia, state that during the festival Hekate is also given offerings of garlic – but I can’t find the source of that.
This festival seems to have little to nothing to do with storms, harvests or propitiation and so doesn’t really match up with the modern festival very well in that way. But the date is quite significant and cannot be ignored.
It is worth noting too that James Frazer (Golden Bough) notes that Nemoralia is the festival that was eventually turned into the Feast of the Assumption, this doesn’t seem important at all until we look at the above quote from our oldest modern reference, the Goddess Book of Days. “The 13th. Celebration of Diana and Hecate of the Moon in pre-Hellenic Greece, to protect the harvest. Origin of the Assumption Day in the Church Mary cycle. “
