R code to produce a simple date and clock plot in Roman numerals & Latin text (Gregorian) and Latin (Roman calendar). Works on a 24-hour system. Clock plot based on a modified version of caroline::plotClock.

1. Install the following libraries in R:

• caroline
• lubridate
• rstudioapi

You can do this easily with the following command:

install.packages(c("caroline", "lubridate", "rstudioapi"))

2. Download the Roman festivals (feriae) dataset (feriae.RData) and Latin number names dataset (RomNumNam.RData) into the source directory (i.e., the directory in which the script RomanDateClock.R lives).

3. Run the script RomanDateClock.R in R, then you're ready to plot a real-time date and clock in Roman numerals & Latin.

• Note that there is no zero in Roman numerals (the Romans had no need for it, apparently). I've therefore just incuded '00' when the hour or minute = zero in the 24-hour clock.
• While the time follows the modern 24-hour clock, it's worth noting that the Romans divided the time between sunrise and sunset into equal increments. This means that winter 'hours' were shorter than summer 'hours'. Generally, they referred to the 'first hour', 'second hour', ..., 'noon' (meridies), etc.
• I have provided the time in Latin text as well below the Roman numeral time display: e.g., the time 15:49 is spelt out as qvindecim vndeqvinqvaginta; note that when the hour = 00, I have replaced nihil ('nothing') with media nocte ('midnight')
• Top date is the Gregorian date in Roman numeral format (DD.MM.YYYY).
• Also provided is the Roman calendar date in in Latin. Briefly, the date format follows these rules:
  • there are seven days in the week as in the modern week (but in Latin — Dies Lvnae, Dies Martis, Dies Mercvris, Dies Iovis, Dies Veneris, Dies Satvrni, Dies Solis)
  • months are the same as modern months (but in Latin — Ianvarivs, Febrvarivs, Martivs, Aprilis, Maivs, Ivnivs, Ivlivs, Avgvstvs, September, October, November, December)
  • the 1^st of every month is a Kalends
  • the 13^th (Jan, Feb, Apr, Jun, Aug, Sep, Nov, Dec) or the 15^th (Mar, May, Jul, Oct) are the Ides
  • the Nones are 8 days prior to the Ides
  • All other days work backward from the next 'special day' (i.e., Kalends, Nones, or Ides), + 1 to account for the day itself
  • if the date falls on the day before a special day, it receives the precursor Pridie ('the day before') before the name of the relevant special day
  • the reference year is the founding of Rome as a city (753 BC)
  • if the day happens to be be a Roman festival day (feriatum; those Romans partied a lot), then the relevant feriatum will be indicated; if it is not a festival day, the feriatvm will return nvllvs (none).

Some examples of the Roman calendar in Latin:

• 'Est Dies Mercvris ante diem XI Calendas Maivs MMDCCLXXV Ab Vrbe condita ... feriatvm : Parilia' means 'It is Wednesday the eleventh day before the Kalends of May, 2775 years since the city (of Rome) was founded ... holiday: Festival in honour of Pales, the tutelary divinity of shepherds' (i.e., 20 April 2022)
• 'Est Dies Satvrni ante diem VII Calendas Ianvarivs MMDCCLII Ab Vrbe condita ... feriatvm : Dies Natalis Solis Invicti' means 'It is Saturday the seventh day before the Kalends of January, 2752 years since the city (of Rome) was founded ... holiday: Birth of the Invincible Sun' (i.e., 25 December 1999)
• 'Est Dies Solis ante diem III Idibvs Febrvarivs MMDCCXLIII Ab Vrbe condita ... feriatvm : nvllvs' means 'It is Sunday the third day before the Ides of February, 2743 years since the city (of Rome) was founded ... not a holiday' (i.e., Nelson Mandela released from prison; 11 February 1990)
• 'Est Dies Lvnae ante diem V Nonas Ivlivs MMDCCXLII Ab Vrbe condita ... feriatvm : nvllvs' means 'It is Monday the fifth day before the Nones of July, 2742 years since the city (of Rome) was founded ... not a holiday' (i.e., Tiananmen Square massacre begins; 03 July 1989)