The positivist calendar was an attempt at calendar reform put forward by Auguste Comte in 1849 that used 13 months of 28 days rather than the Gregorian Calendar's 12 months of 30/31 days in adherence with his scientific study of society, Positivism. The calendar was a revision of the earlier eternal calendar developed by Marco Mastrofini, which also used 13 months of 28 days, and, like the positivist calendar, included a 365th day that didn't fall into any month. Mastrofini himself revised earlier concepts from Hugh Jones, who published under the pen name of "Hirossa Ap-Iccim", the Georgian Calendar, a year made of 13 months of 28 days, named after George II, though it lacked a 365th day, making it 364 days.See In the positivist calendar the last day of the year was designated as a festival day to commemorate the dead.
This extra day added to the last month was outside 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 pariahs and outcastsComte, Auguste (1909) . Catéchisme Positiviste ou Sommaire Exposition de la Religion Universelle [Positivist Catechism or Exposition Summary of the Universal Religion] (in French) (Nouvelle ed.). Rue des Saints-Pères, Paris, Île-de-France, France: P.-F Pécaut. pp. 385–386. ., would join the memorial day of the dead. The scheme followed the Gregorian calendar rules for determining leap years, and started on January 1. Year 1 "of the Great Crisis" (i.e. the French Revolution) was equivalent to 1789 in the standard Gregorian system.
Much like Comte's other ideas, the positivist calendar never saw widespread use.
Calendar
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 Georgian calendar nor after Parisian agriculture as in the French Republican calendar but after figures of history in various fields. Weeks and days were also dedicated to great figures in history as a secular version of the concept of saint's days. In all, the Positivist Calendar "contains the names of 558 great men of all periods, classified according to their field of activity." Villains of history were also commemorated in order to be held up for "perpetual execration". Napoleon, according to Comte, was especially deserving of this fate.
Months were named: Moses - Initial religiosity Homer - Ancient poets Aristotle - Ancient philosophers Archimedes - Ancient science Caesar - Military civilization Saint Paul - Catholicism Charlemagne - Feudal civilization Dante - Modern epics Gutenberg - Modern industry Shakespeare - Modern drama Descartes - Modern philosophy Frederick - Modern politics Bichat - Modern science As the positivist calendar more perfectly follows the sun's cycle, each day is the same day as the prior year, for example, the 21st of April, 2026 is a Tuesday, however the 21st of April, 2025 was a Monday. In the positivist calendar, both of these days would be Tuesdays. Taking advantage of this, August Comte named each day of the year, so, rather than being Tuesdays, both of these days are Hipparchus, though the original week names were also preserved. In general, the names listed get more and more modern as the year continues, with the first and oldest being Prometheus, the primordial inventor of fire in greek mythology and the last and newest being Franz Josef Gall, the father of phrenology. The names in each month follow the general themes of the name of the month (e.g Plato is a day in Aristotle). The following table is the full positivist calendar. Day1st Week2nd Week3rd Week4th WeekMoses1st dayPrometheusBelus and SemiramisFuxiAbraham and Joseph2nd dayHercules and TheseusSesotrisLaoziSamuel3rd dayOrpheusMennoMeng-TsuSolomon and David4th dayUlyssesCyrusTibetan MonksIsaiah5th dayLycurgusZoroasterZen/Japanese MonksJohn the Baptist6th dayRomulusThe Druids and OssianManco Cápac and KamehamehaHarun al-Rashid and Abd al-Rahman III7th dayNumaBuddhaConfuciusMuhammadHomer1st dayHerodotusScopasAesop and PilpaiEnnius2nd dayTyrtaeus and SapphoZeuxisAristophanesLucretius3rd dayAnacreonIctinusTerence and MenanderHorace4th dayPindarPraxitelesPhaedrusTibullus5th daySophocles and EuripidesLysipposJuvenalOvid6th dayTheocritus and LongusApellesLucianLucan7th dayAeschylusPhidiasPlautusVirgilAristotle1st dayAnaximanderSolonAristippusXenocrates2nd dayAnaximenesXenophanesAntisthenesPhilon of Alexandria3rd dayHeraclitusEmpedoclesZenoJohn the Evangelist4th dayAnaxagorasThucydidesCicero and Pliny the YoungerSaint Justin and Saint Irene5th dayDemocritus and LeucippusArchytas and PhilolausEpictetus and ArrianClement of Alexandria6th dayHerodotusApollonius of TyanaTacitusOrigen and Tertullian7th dayThales of MiletusPythagorasSocratesPlatoArchimedes1st dayTheophrastusEuclidEudoxus and AratusVarro2nd dayHerophilosAristaeusPytheas and NearchusColumella3rd dayErasistratusTheodosius of BithyniaAristarchus and BerossusVitruvius4th dayCelsusHeron and CtesibiusEratosthenes and SosigenesStrabo5th dayGalenPappus of AlexandriaPtolemyFrontinus6th dayAvicenna and AverroesDiophantusAl-Battani and Nasir al-DinPlutarch7th dayHippocratesApolloniusHipparchusPliny the ElderCaesar1st dayMiltiadesPericlesJunius BrutusAugustus and Maecenas2nd dayLeonidasPhilipCamillus and CincinnatusVespasian and Titus3rd dayAristidesDemosthenesFabricius and RegulusHadrian and Nerva4th dayCimonPtolemy LagusHannibalAntoninus and Marcus-Aurelius5th dayXenophonPhilopoemenPaul-EmilePapinian and Ulpian6th dayPhocion and EpaminondasPolybusMarius and The GracchiSeverus Alexander7th dayThemistoclesAlexanderScipioTrajanSaint Paul1st daySaint Luke and Saint JamesConstantineSaint Benoist and Saint AntoineSaint Francis Xavier and Ignace de Loyola2nd daySaint CyprianTheodosiusSaint Boniface and Saint AustinSaint Charles Borromeo and Federico Borromeo3rd daySaint AthanasiusSaint Christopher and Saint BasilSaint Isidore and Saint BrunoSaint Teresa and Saint Catherine of Siena4th daySaint JeromeSaint Pulcheria and MarcianLanfranc and Saint AnselmSaint Vincent de Paul and Abbey of San Galgano5th daySaint AmbroseSaint Genevieve of ParisHelen and BeatriceLouis Bourdaloue and Claude Fleury6th daySaint MonicaSaint Gregory the GreatThe Architects of the Middle Age and Saint BenezetWilliam Penn and George Fox7th daySaint AugustineHildebrandSaint BernardJacques-Bénigne BossuetCharlemagne1st dayTheodoric the GreatCharles MartelSaint Leo the Great and Leo IVSaint Clotilde2nd dayPelagiusEl CidGerbert and Peter DamianSaint Bathilda and Saint Matilda of Tuscany3rd dayOtto the Great and Henri l'OiseleurRichard and SaladinPeter the HermitSaint Stephen of Hungary and Matthias Corvinus4th daySaint HenryJoan of ArcSuger and Saint EloiSaint Elizabeth of Hungary5th dayVilliers and La ValetteAlbuquerque and Walter RaleighAlexander III and Thomas BecketBlanche of Castile6th dayJohn of Austria and John SobieskiBayard (knight) or Bayard (horse)Francis of Assisi and Saint DominicSaint Ferdinand III and Alphonso X7th dayAlfredGodfrey of BouillonInnocent IIISaint LouisDante1st dayThe TroubadoursLeonardo da Vinci and the TitianFroissart and John of JoinvillePetrarch2nd dayBoccaccio and ChaucerMichelangelo and Paolo VeroneseCamoensThomas à Kempis and Louis of Granada3rd dayRabelaisHolbein and RembrandtSpanish RomanticistsMme. de Lafayette and Mme. de Staël4th dayCervantesPoussin and LesueurChateaubriandFénelon and Saint Francis de Sales5th dayLa FontaineDiego Velázquez and Alonzo CanoWalter Scott and CooperKlopstock and Gessner6th dayFoëx and Edmund SmithTeniers and RubensManzoniByron and Élisa Mercœur7th dayAriostoRaphaelTassoMiltonGuttemberg1st dayMarco Polo and ChardinBenvenuto CelliniStevin and TorricelliBernard Palissy2nd dayJacques Cœur and GreshamAmontons and WheatstoneMariotte and BoyleGuglielmini and Riquet3rd dayGama and MagellanHarrison and Pierre LeroyPapin and WorcesterDuhamel (du Monceau)4th dayNeper and BriggsDollond and GrahamBlackSaussure and Bouguer5th dayLacaille and DelambreArkwright and JacquartJouffroy and FultonCoulomb and Borda6th dayCook and TasmanContéDalton and ThilorierCarnot and Vauban7th dayColumbusVaucansonWattMontgolfierShakespeare1st dayLope de Vega and MontalvanTirsoAlarconPergolèse and Palestrina2nd dayMoreto and Guillén de CastroVondelMme de Motteville and Mme RolandSachini and Grétry3rd dayRojas and GuevaraRacineMme de Sevigne and Lady MontaguGluck and Lully4th dayOtwayVoltaireLesage and SterneBeethoven and Handel5th dayLessingMetastasio and AlfieriMme de Staal and Miss EdgeworthRossini and Weber6th dayGoetheSchillerFielding and RichardsonBellini and Donizetli7th dayCalderonCorneilleMolièreMozartDescartes1st dayAlbertus Magnus and John of SalisburyHobbes and SpinosaGrotius and CujasRobertson and Gibbon2nd daySaint Bonaventure and JoachimPascal and Giordano BrunoFontenelle and MaupertuisAdam Smith and Dunoyer3rd dayRoger Bacon and Raimond LlullLocke and MalebrancheVico and HerderKant and Fichte4th dayRamus and The Cardinal of CusaVauvenargues and Mme de LambertFréret and WinckelmanCondorcet and Ferguson5th dayMontaigne and ErasmeDiderot and TracyMontesquieu and d'AguesseauJoseph de Maistre and Bonald6th dayCampanella and MoreCabanis and Georges LeroyBuffon and OkenHegel and Sophie Germain7th daySaint Thomas Aquinasthe Chancellor BaconLeibnitzHumeFrederick1st dayMaria de MolinaColigny and L'HôpitalXimenesSidney and Lambert2nd dayCôme de Médicis l'AncienBarneveldtSully and OxenstiernaFranklin3rd dayPhilippe de Comines and GuicciardiniGustavus AdolphusColbert and Louis XIVWashington and Koscusko4th dayIsabella of CastilleDe WittWalpole and MazarinJefferson5th dayCharles V and Sixtus VRuyterD'Aranda and PombalBolivar and Toussaint Louverture6th dayHenri IVWilliam IIITurgot and CampomanesFrancia7th dayLouis XIWilliam the SilentRichelieuCromwellBichat1st dayCopernicus and Tycho BraheViète and HarriottBergmann and ScheeleHarvey and Ch. Bell2nd dayKepler and HalleyWallis and FermatPriestley and DavyBoërhaave and Stahl3rd dayHuyghens and VarignonClairaut and PoinsotCavendishLinnaeus and Bernard de Jussieu4th dayJacob Bernoulli and Johann BernoulliEuler and MongeGuyton-Morveau and GeoffroyHaller and Vicq-d'Azyr5th dayBradley and Roc̈merD'Alembert and Daniel BernoulliBertholletLamarck and Blainville6th dayVolta and SauveurLagrange and Joseph FourierBerzélius and RitterBroussais and Morgagni7th dayGalileoNewtonLavoisierGall The first day of the year is Prometheus, the Festival day the last day of the year, not the first.
The original french states "Menou" which could, tentatively, potentially refer to general Menou, and could also potentially refer to Menus of Megara or even Memnos. While the theologic nature of the names of the days of the month of Moses points to Menno, the founder of the mennonites, Menno is out of place chronologically, being the youngest in the month, as a figure from the 16th century, nearly a century after the next youngest in Moses, Muhammad.
The original french states "Ulysse", which could be translated as either Ulysses or Odysseus, Ulysses/Ulysse is more common in French, and while both are used in English, Odysseus is more common.
Could also be referring to Ictinus of mythology.
The original french "Phédre" could potentially, though very unlikely, refer to Queen Phèdre, the protagonist of the tragedy of the same name, or Phaedra of mythology.
Could also refer to Anaximenes of Lampsacus, likely both.
Likely referring to Aristippus the Elder and Aristippus the Younger, not Aristippus of Larissa or Aristippus of Argos.
Likely referring to Antisthenes of Rhodes rather than Antisthenes the cynic, due to the inclusion of the other historian, Herodotus earlier in the month of Aristotle.
There are many people named Polybus this could refer to.