Mid-Winter's Day arrived, cool and clear. Jame, Dally, and Canden went to Judgment Square to see the apotheosis of the Frost King,
– Jame's narration, God Stalk, "Chapter 6: Water Flow, Fire Leap"
Mid-Winter's Day on the Tastigon Calendar is exactly the middle of the 120-day winter season. Unlike our own calendar, the Tastigon year does not begin at this time, but 60 days later on Spring's Day. Mid-Winter's day should also not be confused with the Winter Solstice, which is a few days off.
↑Bound in Blood, "Chapter XIII: A Day in the Life", VI — " 'Every Mid-Winter's Day, the whole college stages a campaign, to test our skills, to ward off cabin fever, to give us points toward our eventual placement as second-year cadets.' "