"The Kitchen Knight" has this plot element: https://www.penguinrandomhouse.ca/books/590413/the-kitchen-k...
In this version it's the Red Knight who is strongest at noon (IIRC).
In this version it's the Red Knight who is strongest at noon (IIRC).
"According to the Vulgate Mort Artu, Gawain had been baptised as an infant by a miracle-working holy man, also named Gawain, who named the boy after himself, and the following day announced that every day at noon, at the hour of the baptism, his power and strength will increase."