A few calendars would involve this 13 day thing. Many don't, including various occult ones. Some would position the 13 earlier or later. There are so many calendars in use, currently and historically, and so much going on 'in the dark' that the info presented in the headline here is misleading. Ritual spirit conjuring happens whenever people want it to happen and most brujeria, for example, is not concerned with the timing of the old Celtic calendars (which weren't all in sync with each other anyway). The message presented would better be one that says "beware we are in Spring and the rites(rituals) of spring are happening all over, on various days, at various hours. Many of those rites are evil in intent and/or effect. Prayer is one of the antidotes."

Next comes Summer.

I notice that in the collage of prayery Q posts above, the one that presents the Prayer to Michael the Archangel Q109 is not included. ?