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Hogswatch
From Discworld & Pratchett Wiki
Many Roundworld traditions have their counterpart on Discworld: carol singing, presents, warm alcoholic drinks, giant department stores with grottoes - even a Wenceslas-type king/peasant scenario that Death and Albert quickly reverse.
Another Hogswatch tradition is that Witches must not go out that night. Like other rules, this one is observed at the discretion of the Witch. The festival features most prominently in Hogfather, and was actually first mentioned in the pre-Discworld novel The Dark Side of the Sun. It is mentioned that the origins of Hogswatch occurred during winter,when a kind king was passing a cottage and heard 3 sisters weeping over having no food to eat. The king took pity and threw a bag of sausages at them (knocking out one of them, but no-one cares).
Image by Matt Smith.