Well, you've missed "Feast Of The Larvae" - so you probably shouldn't make a maggot cake.
Actually about ghosts:
http://pagancalendar.co.uk/event.php?zodiac=astrological&getdate=20130517&tz=Europe/London&id=1043
"In Roman mythology, the larvae or lemures were the spectres or spirits of the dead; they were the malignant version of the lares. Some Roman writers describe lemures as the common name for all the spirits of the dead, and divide them into two classes: the lares, or the benevolent souls of the family, which haunted and guarded the domus or household, and the larvae, or the restless and fearful souls of wicked men. But the more common idea was that the Lemures and Larvae were the same. They were said to wander about at night and to torment and frighten the living."
You could make a cake that keeps someone up at night?