what spells w/could be used on the various holidays?
The one spell that I've seen used on holidays a lot is a spell to cure drunkenness. Often used when a story gets underway and the useful people are blotto.
Make sure to have high penetration, or you may find it tricky to pull off on your drunken older amici - Parma is just as effective when you're drunk, but supressing it is hard when snoring on the floor or making bibbledy noises into your mug.
Would a drunk as a skunk magi really, i mean REALLY, wake up at dawn to renew the parma and then go back to sleeping it off?
Totally doubt it! :mrgreen:
Damn! All those years studying penetration and finesse to aim boulders when available and it turns out that the best hoplite skill is carouse!
Around my covenants "Apprentice's Merry Feast" and "Great Revel of the Turb" (one barrel and a group of barrels water turned to wine for Sun-duration) is the really handy spell. At sunrise all effects disappear (including the hang-over) since everyone has only been drinking wine.
Very nice way to have fun and to be popular with the mundanes. And a mandatory spell for any apprentice to research herself (to train lab-work and spell design) and as an exercise in Finesse (to make it drinkable).
Apprentices low on Muto and/or Aquam frequently end up with "Apprentice's Petty Feast" which can only transform a bottle or (with a deficiency) only a single cup of water 
Guess why we´ve used parma as an automatic ability for a loooong time? :mrgreen:
Nah, the wine was real, so the aftereffects stick around. 
Totally agree. I've never understood this insistence that magically-created wine doesn't cause hangovers. It's like saying that the wounds caused by magically-created swords disappear when the spell ends.
Hangovers are an accumulation of corrupt humours building up in the nerves. The continued existence of the agent of this plethora is not necessary.
Mark
I see your point, then somebody could say the same with food and his nourishment and so on, I'd say taht while is in effect should work like the common efect if the spell penetrates and so.
Not really the same thing. Food is transformed by the various concoctions of the bodily organs into the humours and faculties. Magically created food has none of the necessary life-giving qualities of natural food.
Strong liquor, poison, and swords on the other hand have the capacity to hurt even if they are magically created. Spells to destroy poison inside someone's body should prevent any further damage but not heal any wounds already caused (although I notice with some surprise that Alleviate the Serpent's Bite is not a 5e spell). A spell that heals damage caused by poison (Gentle Touch of the Purified Body) specifically heals the wound, but if the victim is still poisoned, does not prevent further damage from occurring.
(Caveat: I'm not sure how much of my food argument is post hoc justification of how the rules work).
It would be a relatively simple spell to purge the body of the morbid humours caused by over-indulgence, based on the Level 3 guideline from Art & Academe: invoke a minor symptom of a disease without creating any underlying malaise (e.g. rash, mild fever, cough)
Hair of the Dog
Rego Corpus 4
R: Eye, D: Mom, T: Ind
The target of this spell immediately discharges corrupted humours from his nerves, which emerge through his nose as a thick grey mucus, and from his eyes as tears. This clears the body of the effects of overindulgence in strong drink, but cannot restore any Fatigue loss
(Base 3, +1 Eye)
Mark
Any spells for other holiday effects?
Mark, i understood; Why hangover no when poisoning yes, I got it (too to acid and fire and so on).
I supose taht we can ask about what is a consecuence and what is one effect/propierty (ruled by the Vis Limit). The burn, the wounds and so on are consequences of one sustance, where the heat, the taste and so on are properties of it.