The Question and Answer section for Sir Gawain and the Green Knight is a great resource to ask questions, find answers, and discuss the novel.
We are shown the festive scene at King Arthur's castle. There is much food and opulence:
For there the feast was held full fifteen days alike with all the meat and the mirth that men could devise. Such a merry tumult, glorious to hear; joyful...
He challenges the Green Knight for King Arthur.
It is the New Year’s Eve feast at King Arthur’s court.