The positivist calendar was a calendar reform proposal by Auguste Comte in 1849. Revising the earlier work of Marco Mastrofini, or an even earlier proposal by "Hirossa Ap-Iccim" (=Rev. Hugh Jones), Comte developed a solar calendar with 13 months of 28 days, and an additional festival day commemorating the dead, totalling 365 days.
This extra day added to the last month was outside of the days of the week cycle, and so the first of a month was always a Monday. On leap years, an additional festival day (also outside the week cycle), to celebrate holy women, would join the memorial day of the dead. The scheme followed the Gregorian calendar rules for determining which years are leap years, and started on January 1. Year 1 "of the Great Crisis" according to this calendar would be equivalent to the year 1789 in the Gregorian system.
Much like Comte's other schemas, the positivist calendar never enjoyed widespread use.
The months were named, in chronological historical order, for great figures in Western European history in the fields of science, religion, philosophy, industry and literature. Each day of the year was named after neither Catholic Saints as in the Gregorian calendar nor after Île-de-France agriculture as in the French Republican calendar but after figures in history in various fields.
Months were named:
- Saint Paul
In 1849, Comte wrote that he called his calendar a "breach of continuity" with the old way of thinking, and his Humanistic calendar was part of that breach. He called it, "a provisional institution, destined for the present exceptional century to serve as an introduction to the abstract worship of Humanity."
Aside from the religious references the calendar carried, Duncan Steel, author of Marking Time, believes the novelty of the calendar's month names alone helped prevent the wide acceptance of this proposal.
The main reason that his suggestion [for calendar reform] failed to find favor with many people seems to have been that he insisted on naming the months for various notable persons from historical to modern times, ... One must admit that it would seem strange to give the date as the third day of Homer, and with a month named for the bard a reference to "Shakespeare's Twelfth Night" would be ambiguous.
Author Tricia Lootens writes that the idea of naming days after literary figures, as if they were Catholic Saint days, didn't catch on outside the Positivist movement.
Outside of positivist circles, canonization of literary secular saints was nearly always slightly tinged with irony or nostalgia, and positivist circles were never large.
See also 
- Comte, A: "System of Positive Polity", page 346. Longmans, Green and Co. 1877 edition.
- Steel, D: "Marking Time: The Epic Quest to Invent the Perfect Calendar", page 308. John Wiley & Sons, Inc. 2000.
- Lootens, T. Lost saints: silence, gender, and Victorian literary canonization, page 15. University of Virginia Press. 1996.
- Interactive positivist calendar from positivists.org
- Calendrier positiviste, Auguste Comte, April 1849 (1993 re-edition). Scanned pages as PDF from Gallica.
- Calendrier positiviste, Catéchisme positiviste, ou Sommaire Exposition de la religion universelle en treize entretiens systématiques entre une femme et un prêtre de l'humanité, Auguste Comte, Apostolat positiviste (Paris), 1891. From Gallica - Bibliothèque Nationale de France.
- The Thellid Calendar is a modern calendar similar to the Positivist calendar.
- Philosopher's Calendar is an adaptation of the positivist calendar for Android devices.