calcalr

WORK in PROGRESS

The calcalr package implements the algorithms of the book

E. M. Reingold, N. Dershowitz “Calendrical Calculations - The Ultimate Edition”, Cambridge University Press, April 2018

Concepts

The easiest way to reckon time is simply to count days. Reingold and Dershowitz have chosen midnight at the onset of Monday, January 1, 1 (Gregorian) as the fixed date 1, which is abbreviate as R.D.¹ 1.

An R.D. that has a fractional part giving the time of day is called a “moment”. So noon on day i would be specified by $i + 0.5$.

All calendars provide conversion functions to/from R.D. making it possible to convert from any one calendar to any other one.

Installation

You can install the development version of calcalr from GitHub with:

# install.packages("devtools")
devtools::install_github("espinielli/calcalr")

Example

This is a basic example which shows you how to solve a common problem:

# library(calcalr)
## basic example code

Footnotes

1. R.D. stands for Rata Die, or fixed date in Latin. ↩