The COP31 presidency has published a theme for each of the twelve days, running from Food, Agriculture and Health on 9 November to Final Negotiations on 20 November.
The themes matter practically, not just symbolically. Pavilions build their programmes around them, so the theme of the day tells you roughly what the whole building will be discussing and which ministers are likely to be present.
Zero Waste has its own day on 11 November, which is also day one of the Leaders Summit. That pairing is the single most crowded slot of the conference for anyone working on waste, reuse or circularity.