“He is the One Who made the sun a radiant source and the moon a reflected light, with precisely ordained phases, so that you may know the number of years and calculation ˹of time˺. Allah did not create all this except for a purpose. He makes the signs clear for people of knowledge.” [10:5]

Reconstructing the chronology of early Islamic history has long been a central pursuit for historians and astronomers alike. Over the centuries, scholars have approached this challenge through various methods, from early foundational attempts tied to solar eclipses¹ and arithmetical tabular calendars² to, recent shifts toward, observation-driven methodologies³.

Building upon these modern frameworks, this study seeks to reconstruct a continuous, highly accurate Hijri calendar spanning the entire lifetime of the Prophet Muhammad ﷺ from his birth to his demise. The primary objective is to provide an accessible historical timeline that mirrors present-day calendars governed by actual crescent visibility rather than rigid arithmetic cycles.

To achieve this, the script integrates high-precision JPL DE441 ephemeris data via the Skyfield library, with ΔT (Delta-T) calculated using the Fred Espenak and Jean Meeus model⁴. Unlike the Tabular Islamic Calendar, which relies on fixed alternating month lengths, this model simulates authentic observational practice.

The script first calculates an approximate starting Julian Date for the target lunar month using the mean synodic month length, locates the true astronomical conjunction preceding that month, and evaluates Mohammad Odeh’s (2004)⁵ crescent visibility criteria on the 29th day of the lunar cycle to determine whether the month consists of 29 or 30 days, securely locking onto the precise calendar start date. Finally, it processes subsequent months forward sequentially, maintaining observational consistency across the entire timeline.

The core calendars within this compilation are organized as follows:

• 53 BH to 1 BH: Structured under the Makkan observational baseline.

• 1 AH to 11 AH: Structured under the Madinan observational baseline.

For deeper analysis and data transparency, two appendices are provided:

• Appendix 1: Makkan-based calendars spanning from 1 AH to 11 AH for comparative historical analysis.

• Appendix 2: Detailed monthly astronomical data logs.

Beyond its technical execution, this observation-driven reconstruction yields striking chronological consistency. Notably, the generated calendar naturally aligns with foundational prophetic traditions, placing both the birth of the Prophet ﷺ and the onset of revelation precisely on Mondays, as documented in Sahih Muslim.

Ultimately, this work aims to bridge a long-standing gap in historical studies by providing a robust, observationally grounded Islamic calendar for the entirety of the Prophet's life ﷺ.

| Download The Prophetic Epoch an Observational Seerah Calendar📥|

SHA256: 5ab2c4eaf6e554a7f2ea5d94aaeca0fab4a0ea99cb39087a2265a4eb62de95f2