The absence of a historical dimension and the scant attention paid to the religious aspect of the question are the most notable limitations of the specialized literature on calendars during the nineteenth century and into the first decade of the twentieth century. Thus, such monumental works as L. Ideler's Handbuch der mathematischen und technischen Chronologie (Berlin, 1825–1826), F. Ginzel's work of the same title (Leipzig, 1906–1911), and even the entry "Calendars" in James Hastings's Encyclopaedia of Religion and Ethics, vol. 3 (Edinburgh, 1910), although they provide indispensable information, amount to little more than unconnected descriptions of various calendars. These descriptions are not satisfactorily situated against the background of the cultures in question, but are treated as if they are solely concerned with chronology and astronomy.

The sacral aspect of the question has, however, been discussed in the subsequent scientific literature, in which the specialists are divided into two opposing camps...