On November 21st, the following events occur in Catville related to various individuals and their AI projects:

1. Peter meets Samantha at the park and suggests they meet under the oak tree next Monday at 14:00 to discuss their AI project plans. Samantha agrees and will bring her laptop for the meeting.

2. Noor, who had been catching up with Andy at Caroline's café earlier in the day, informs Peter that she is also part of the AI project discussion and will be attending the meeting under the oak tree tomorrow. Andy suggests moving the meeting from 3 PM to 2 PM at the café instead due to schedule changes.

3. Diego runs into Noor at the park and they discuss their shared AI project progress. Diego proposes that they meet at Caroline's Café tomorrow at exactly 2 PM for their AI project discussion, as he has made some adjustments to his schedule.

4. Samantha and Mei meet at the library cafe and discuss some intriguing archives that they found. They plan to continue their discussion over vegan street tacos tomorrow afternoon at 3 PM, with Mei offering to treat them both.

5. Caroline and Mei catch up at a restaurant and discuss their shared interest in AI projects. Mei offers to continue the discussion over vegan street tacos tomorrow afternoon at 3 PM at a place of their choosing, which aligns with her previous offer to treat them both.

The following day, various individuals will be meeting under the oak tree or at Caroline's Café to discuss their AI projects: - Peter, Samantha, and Noor will meet under the oak tree at 9 AM, possibly grabbing tea beforehand as planned with Andy. - Diego, Noor, and others (including perhaps Andy) will meet at Caroline's Café at exactly 2 PM for their AI project discussion. - Samantha and Mei will have lunch together over vegan street tacos at an agreed upon location, continuing their discussion on the intriguing archives they found.