CAL-8059Folder 09 — Source Cards
Source Card — Calendar Astronomy
U.S. Naval Observatory, Astronomical Applications Department
For year lengths, leap rules and the accumulated Julian-Gregorian difference, the archive uses a government astronomical reference rather than any confessional source.
ASTRONOMY
Publisher
U.S. Naval Observatory, Astronomical Applications Department — calendar reference and FAQ material covering the Julian and Gregorian systems, tropical year length and the mechanics of the 1582 reform.
Why it is filed separately
None of the astronomy in this quest is disputed between East and West. Keeping it in a neutral folder makes clear that the disagreement lives in ecclesiology and history, not in measurement.
Citations on this file
Sources
- USNO Astronomical Applications — calendarsTropical year, Julian and Gregorian leap rules, and date-difference arithmetic.https://aa.usno.navy.mil/faq/calendars ↗
Links are pointers for further reading. The claim is what is sourced, not the website.