Humans are the worst species aren’t we

It's definitively not the source of the word, but it might very well be the reason the decided to have a "fest i val". Gothenburg is famous for their puns, and even today they open up the mouth of the whale for visitors on two occasions - valdagen (election day) and Valborgsmässoafton (Walpurgis eve).

It surely is; 'fest' is the Swedish word for 'party'. I actually think Swedish or Norwegian (which are practically the same language) are closer to English than even Dutch. Many of the most common, short English words are the same.

Wiktionary says

> From Middle English festival (adjective), from Old French festival (“festive”), from Late Latin fēstīvālis, from Latin fēstīvus (“festive”). By surface analysis, festive +‎ -al. Displaced native Old English frēols. The noun is shortened from festival day, from Middle English festival dai, festiuall day (“feast day, festival”).

https://en.wiktionary.org/wiki/festival