It is an elaborated and amended version of John of Gmunden’s Kalendarium (Calendar), a widespread cyclic calendar used to get reliable syzygy times for liturgical and astrological purposes..[1] One of the key features of this manuscript is its codicological format: in contrast to the traditional codex, organised in quires, Latin 7478 is composed of individual folded leaves attached together, which are to be unfolded and read from the outer edge to the stub.

However, some of the scholars presume that at least two people have been involved in the production of Latin 7478: a rather skilled almanac-maker, able to abbreviate diagrams and tables with a minimal loss of information, and a less experienced scribe, able to adapt 19-years cycles to a required date, lacking the knowledge to perform this procedure without distorting the time of syzygies.

1) of Latin 7478 contains a circular diagram dividing the years into 19-year cycles accompanied by the canon entitled “Ad sciendum per kalendarium sequens tempus conjunctionum et oppositionum solis cum lune <...>” .

In addition, the astrological aphorisms attributed to Regimen sanitatis Salernitanum (The flower of medecine a didactic poem in the subject of medicine) can be found at the same folded folio.

This reflects the production of astro-medical compendium for traveling physicians, which follows a larger medieval tradition of using astrological knowledge to calculate the ideal time for surgical procedures or to predict the days of potential crises during the course of the illness.

[11] Such physician’s almanacs were often produced in the forms of “bat-books” and sometimes contained purely medical texts and illustrations alongside the astronomical tables (an example of such almanac is the British Library manuscript Harley MS 3812)[12] This section is representative of the growing trend (starting late 13th-early 14th century) to enhance the traditional kalendarium format with the more advanced prediction methods using the astronomical tables.

[13] Folio 17 of Latin 7478 contains a diagram combining a didactic cosmographical system (represented in the form of concentric circles, one for each of the four elements) and a small geographical mappa mundi (a term used for medieval European map of the world).