CalculationTime

ChronoSyncline Calendar

Time Duration Calculator
CalculationTime

ChronoSyncline Calendar

A calendar observatory for historical cutovers, phantom dates, sunset-shift layers, Julian day number, moon age, solar longitude and cross-calendar teaching notes.

Inputs, result, proof and time.

Use the instrument above, then check the calculation record, assumptions and related tools below.

Selected instant

2026-09-05

12.0 local hour before sunset boundary
JDN
2461289.00
Calendar
Gregorian
Drift
13 days
Skipped
10 days
Old Style Julian2026-08-2313 day split from New Style
New Style Gregorian2026-09-05Saturday 05 September 2026
Hebrew arithmetic22 Av 5786Regular, Metonic 10/19, regular year
Tabular Islamic22 Rabi al-Awwal 1448 AHSame civil date basis
Chinese Intl24 Seventh MonthYear of the Horse
Chinese estimateMonth 8, Day 24Synodic cycle 79.3%
Moon age23.94 d29.530588861 day lunation
Solar longitude164.6 degModerate heat

Method

Gemini's useful intake has been adapted into a jurisdiction-aware Julian/Gregorian cutover engine with phantom-date detection, dual Old Style/New Style display, Hebrew arithmetic, tabular Islamic output and a labelled Chinese synodic estimate.

Trust boundary

This page preserves Billy's observatory concept as a teaching instrument. It is not an official religious calendar, legal calendar, observatory almanac or location-specific sunset calculator.

Method

The observatory keeps calculated layers and approximations separate

The page uses Gemini's jurisdiction-aware Julian/Gregorian routing idea for historical cutovers, computes a Julian day number from the selected date and hour, derives moon age and solar longitude from compact formulas, and labels Islamic, Hebrew and Chinese calendar layers with visible trust boundaries.

Formula

JDN follows standard Gregorian and Julian conversions. Moon age = (JDN - 2451549.5) modulo 29.530588861 days.

Limit

The Hebrew layer is arithmetic, Islamic output is tabular, the Chinese synodic layer is estimated, and the sunset boundary is a teaching slider rather than a location-specific sunset engine.

Input source

Built from `frombilly/EXCLUSIVECALENDAR.html` plus Billy's Gemini `ChronoSyncline Universal Chronometric Engine`; the truncated downloaded HTML was not copied into production.