Hello!
One thing that has caught my fascination is the relationship between Christianity and its inherited/appropriated Hebrew Scriptures with the Greco-Roman heritage that it acquired with the Christianisation of the Roman Empire. Many of the early Church Fathers believed the classical philosophers had been divinely inspired or that they had read the Old Testament - but what I'm more interested in is the overlap between the conflicting histories of the world presented by the Biblical record and the histories of Antiquity.
I'm very fond of the Nuremberg Chronicle (1493) and the insight it gives into contemporary understanding of the world. Are there similar texts which elide Biblical origin stories with ancient historiography? And how did historians, genealogists, natural philosophers and scientists before the 19th century reckon the age of the Earth, the age of the human species and the histories of different nations, among other things?
In addition to this, I would be fascinated to know from ancient historians about where the Jews thought the Romans had come from. As the Biblical genealogies only attest to the kingdoms and tribes surrounding Israel, how were the encoutners with great foreign powers like Rome received and explained? Same would go for Christian encounters with the New World and Asia.
Thank you!
What you are interested in most likely is Universal Chronicles or Universal History. This is a specific type of medieval chronicle that generally traces history from creation to whenever the writer was writing. The first example the Middle Ages claims is Eusebius (through Jerome's copy), who wrote a chronicle that had 16 columns, each representing a different civilizations. On the left was a column listing years. He gathered all his sources together and entered his data into the columns in the appropriate slots. To him, this was the assemblage of all known knowledge, thus a "universal" chronicle. Things developed from there. The Wikipedia provides some examples and there are resources at the bottom of the page for further info.
For determining time and years, one example would be Bede, who wrote a treatise called On the Reckoning of Time, which explains how to calculate dates and years, specifically the date for Easter.
You might also check out Bridget Ann Henisch. The Medieval Calendar Year (UPenn Press, 1999), which goes into detail about how medieval culture used calendar to help order itself.
Lastly, John Steele edited Calendars and Years: Astronomy and Time in the ancient and Medieval World (Oxford 2011), which gives some more specific information.
Hope this helps a little. Happy reading!