The Babylonian Astronomical Diaries ADART I–III · 417 records

How the sky dates a tablet

For nearly six centuries, scribes in Babylon wrote down the night sky. Many of their tablets have lost their date. Mars, Jupiter and Saturn move on their own cycles, as the hands of a clock do. Lunar eclipses and the solar year do too. Intact, dated reports of these clocks decide which years stay. The other reports, such as the Moon against the stars, then put those years in order.

Follow a tablet

A companion to Automated, auditable dating of the Babylonian Astronomical Diaries with language models and astronomical tools, by L. Carrit Delgado Pinheiro, Y.-S. Ting, J. Clindaniel, L. Li, Y. Liang and N. Shroff.

The diaries report the Moon, the planets, eclipses and the seasons, night after night. The years in which such a report is true repeat on the cycles of the sky. For example, Jupiter comes back to the same sign about every twelve years. Thus the sky alone can narrow the date of a broken tablet that names a few such events.

Choose a tablet, or keep the tablet that the page shows. The page follows it in three steps: the words of its scribe, each planet in it as a clock, and the years that all its clocks allow. A rule-based parser reads the text, and a language model checks the parser and adds what it misses. Astronomical tools and fixed rules then give the years. Each value comes from the open results of the paper.

The scribe

What the tablet says

The clocks

The clocks in the sky

A planet that a scribe saw in a sign in a month agrees with each year in which the planet stood there in that month. On a dial, these years line up. When the dial unwinds onto a line of years, they become a row of marks.

The year

The clocks add up

Each decisive clause adds weight to the years that it agrees with. The rules also count the clocks that agree with each year. The years that no other year beats stay.

Check any year

In the chart of chapter III, select any year to see the verdict of each clause in that year. The tools also keep a written reason for each verdict in the first 12 years of the ranking, in the years that stay when they are 40 or fewer, and in the published year. Choose another tablet at the top, and the page shows the same steps for it.

Words on this page

Clause
One report about the sky, in fixed fields, as the parser or the language model reads it from the translation.
Sign
One of the twelve parts of the zodiac, each 30° wide. The scribes put the Moon and the planets in them.
Station
The time when a planet seems to stop against the stars, before it moves in the other direction.
Acronychal rising
The rising of a planet at sunset, near the time when it stands opposite the Sun.
Clock
An event that repeats on its own cycle: Mars, Jupiter, Saturn, lunar eclipses and the solar year.
Bit
The unit of weight. A clause that agrees with half of the years that the tools can test adds 1 bit.
Decisive and supporting
Decisive clauses decide which years stay. Supporting clauses only put the years in order.
The years that stay
The years that no other year beats on clocks and decisive weight. The paper calls them the strict set.

Cite

L. Carrit Delgado Pinheiro, Y.-S. Ting, J. Clindaniel, L. Li, Y. Liang and N. Shroff, Automated, auditable dating of the Babylonian Astronomical Diaries with language models and astronomical tools, arXiv:2610.34297 (2026).

Data and code

The code is under the MIT License, and the data and figures under CC BY 4.0. The translations of ADART I to III come from Astronomical Diaries Digital (ADsD), released under CC0. Planet positions come from the Development Ephemeris DE441 of the Jet Propulsion Laboratory.

The cuneiform signs come from the ORACC Sign List (CC0), and the page sets them in Noto Sans Cuneiform. We made the paintings, the parchment, the drawings of the signs, the museums and the emblems of the periods of rule, and the pictures of the planets with Gemini 3 Pro Image. They are illustrations, not ancient objects or photographs.