COSTAR Calendar

A subscription calendar carrying the daily events of the COSTAR calendar — lumas, chromas, lunations, lunar phases, solstices and equinoxes. Subscribe once and updates arrive automatically.

https://ics.costar.date/costar-calendar.ics

Google Calendar

  1. Open Settings → Add calendar → From URL
  2. Paste the address above and choose Add calendar
  3. Google names the new calendar after its URL. To rename it: hover the calendar in the sidebar → ⋮ → Settings, and change the Name to “COSTAR Calendar”

Apple Calendar (Mac & iPhone)

  1. Tap or click Subscribe in Apple Calendar
  2. Confirm — the calendar appears as “COSTAR Calendar”

Outlook

  1. Calendar → Add calendar → Subscribe from web
  2. Paste the address above
Display tip: give the COSTAR Calendar a very pale display color in your calendar app — the events use color emoji (🟥 🔴 ⬜⬛ ☀️) and monochrome symbols (● ◐ ○ ◑, α β γ δ ε) that read best on a light background.

Events never mark you as busy. The calendar covers all of Rotundum 1's Alpha Quinquennium — 21 Dec 2025 through 22 Dec 2030; coverage extends over time and reaches you automatically through your subscription.