Added a full calendar view to my visual project tool today — full breakdown of what it took

Users kept asking for deadlines on UluP Spaces (a visual project-mapping app — nodes on a canvas instead of a flat to-do list). Built the whole thing today, solo, in one session.
What shipped:

• Due dates on any node — click-to-set, with a clean UI
• Push notifications: a Supabase Edge Function on a 15-min cron checks for approaching deadlines and sends via Firebase
• A real animated monthly calendar view, matching the app's existing visual language (colored dots per node color, staggered day entrance animation, pulsing "today" indicator)
• A shortcut icon on project cards to jump straight into a project's calendar
  The annoying part: found a genuine bug in the process — native browser date pickers (Chrome specifically) can silently corrupt input if you type fast, overflowing the year field past 4 digits and breaking Postgres timestamp parsing on save. Added explicit validation before any write now, so garbage input gets caught with a clear error instead of a confusing 500.
  Video of it in action: https://youtu.be/6whVdfiiBwE

ulupspaces.com if you want to try it — free.

Happy to talk through the architecture (the cron/notification setup specifically) if useful to anyone building something similar.