I. THE SEVEN-DAY WEEK IN THE ROMAN EMPIRE

The seven-day week stems from two distinct traditions: the biblical week of the Sabbath, and the planetary week.Footnote ² It is in the latter form that the seven-day cycle made its first appearance in the Roman West: the earliest traces of the use of the planetary week appear in Italy during the second half of the first century BC.Footnote ³ Thereafter, in the course of the first centuries of our era, the seven-day week became increasingly widespread throughout the Roman world, as literary, epigraphic and documentary sources show.Footnote ⁴ By the fourth century the habit of measuring time in cycles of seven days — either in the Judaeo-Christian or in the planetary form — became general all across the Roman Empire (Colson, Reference Colson1926: 18).Footnote ⁵

The planetary week is of astrological origin. Each day of this week was named after one of the seven planets or non-fixed heavenly bodies of the universe as it was known in antiquity: the Sun (Sunday), the Moon (Monday), and the five planets, which were named after the gods Mars (Tuesday), Mercury (Wednesday), Jupiter (Thursday), Venus (Friday) and Saturn (Saturday).Footnote ⁶ Although the earliest traces of the existence and use of the planetary week appear in the Italian peninsula, it has been traditionally suggested that this type of week might have been a product of the Hellenized Egypt of the Ptolemies;Footnote ⁷ in particular, both the astrological concept underlying it and the planetary week itself would have originated in the Alexandrian milieu, the foremost cultural and scientific centre of the Hellenistic Mediterranean, where Babylonian astrology was much developed by the Greeks and whence it expanded westward to the Roman world from the late Republican period on. Within this framework, my assumption is that the Romans probably played the fundamental role of putting into practice, for calendrical purposes, a hitherto purely theoretical concept of Greek astrology. In fact, this idea is plausible but not provable, since there are no traces of this particular astrological concept in the extant astrological writings of Hellenistic Egypt. Whether one accepts this hypothesis or prefers to think that the Romans invented the whole system ex novo — a possibility that cannot be totally excluded — it is reasonable to assume that the introduction of the planetary week in the Roman world was at least promoted by the influence that the Egyptian calendrical system as well as further Alexandrian astronomical and astrological ideas exerted over the reformation of the Roman calendar by Julius Caesar in 46 BC and, more generally, over the western Roman world in the late republican and early imperial period.Footnote ⁸ The Romans apparently started employing the astrological theory behind the planetary week as a means of measuring time during a period when Roman scholars and politicians showed an increasing interest in time reckoning and chronology. As the Roman calendar was reformed on the initiative of Julius Caesar, scholars like Varro and Atticus sought to lay the foundation for a consistent chronology of the Roman past.Footnote ⁹ It should be observed, however, that although an actual calendrical use undoubtedly developed quite early, the planetary week seemingly first spread in the Roman West as a purely astrological and astral-lore related concept (Rüpke, Reference Rüpke2011: 162–3). It appears as though it was the belief in the power and control of planets over the hours of the day that led to the adoption of the seven-day week. As an example, when dealing with the Jewish religion, Tacitus states that some people assumed that the sabbatical rest was in honour of Saturn, because, among other reasons, ‘of the seven stars by which mortals are governed, that of Saturn has the widest orbit and the highest power’ (Histories, 5.14.11). Not only do we find here the biblical week linked to the planetary (Colson, Reference Colson1926: 17), but this is also a clear statement of belief in the planetary control of human affairs: what lies behind the days ordering in the planetary week is the belief that the planets control hours and days.

As mentioned, the seven-day week derived from two distinct traditions: the planetary week of astrological origin and the biblical week of the Sabbath, the latter drawing its origin from the Old Testament. The length of the week in this case is related to the seven days of creation in biblical cosmology. The biblical account of creation explains God's commandment to work for six days and rest every seventh day, which for the Jews was (and still is) the Sabbath (Exodus 20:8). Despite the great antiquity of the biblical seven-day cycle, the week was not used as a principle for constructing the calendar in the Bible, nor is there any trace of days of the seven-day week in priestly literature. A change occurs in the Book of Jubilees, which dates to the mid-second century BC, as well as, slightly later, in the Qumran texts. The value of these sources as evidence that the week was used for practical purposes, however, is not certain. The days of the week are still absent from date formulae in the same period and will make their first appearance, on ostraka and administrative texts, in the first century of our era. It appears plausible that the Jews started using the days of the week for practical purposes, as well as for liturgy, in the first century BC (Ben-Dov, Reference Ben-Dov2008: 55–66). However, there are no traces of any connection of the Jewish week with the planetary week, which seemingly first appeared around the same period in the western Roman world. In the week of biblical origin, the days were not each under the patronage of a planet, but simply numbered. The sources indicate that during the imperial period the early Christians adopted the Jewish week and made Sunday, the Christian Lord's Day, the most important day of the week instead of the Sabbath.Footnote ¹⁰

It is interesting to observe that in the sources from the Eastern part of the Roman Empire the seven-day week occurs almost exclusively in the numbered or Judaeo-Christian form. The extant inscriptions with days of this type of week come predominantly from Greece (especially Athens, Corinth and Crete), Thrace, Macedonia and Asia Minor, as well as from the Roman Near East. With a very limited number of exceptions, the planetary week is absent from the textual record of the whole Eastern half of the Roman Empire.Footnote ¹¹ By contrast, the numbered or Judaeo-Christian weekFootnote ¹² is very poorly attested in the epigraphic record of the West, even in the later imperial period and in distinctly Christian milieus. The evidence makes it clear that this type of week did not catch on in the West, at least in everyday usage. Despite attempts by Church Fathers and Christian preachers to eradicate the habit, common people, including Christians, largely continued to name the days of the week after the seven planets throughout the imperial period and in late antiquity, presumably due to the longer tradition of the planetary week in this area of the empire.

II. ECCLESIASTICAL SOURCES

In three of his sermons Caesarius, who was bishop of Arles in southern Gaul in the first half of the sixth century,Footnote ¹³ refers explicitly to the fact that some Christian inhabitants of his diocese observed Thursday as a pagan day of rest.Footnote ¹⁴ In Sermon 13.5, he affirms: ‘The devil has so beguiled some men and women that men do not work and women do not spin wool on the fifth feria’ [ = Thursday] (Aliquos viros vel mulieres ita diabolus circumveniat, ut quinta feria nec viri opera faciant, nec mulieres laneficium). He then proceeds to warn his audience about the dreadful consequences that these men and women are doomed to face by observing the practice of resting on Thursday: ‘They shall be condemned to burn together with the devil’ (u bi arsurus est diabolus, ibi et ipsi damnandi sunt). Shortly afterwards, Caesarius alludes to the fact that this ‘evil practice’ was associated with some form of reverence towards the Roman god Jupiter:

Thus, according to Caesarius, as late as in the sixth century an unspecified number of members of his community (cf. Sermon 13.5: Aliquos viros vel mulieres) — who were presumably Christians, given that they were expected to observe the Lord's Day — observed a Thursday-rest ‘in honour of Jupiter’ and at the expense of the Christian Sunday rest.Footnote ¹⁵

In Sermon 19.4, Caesarius returns to this issue and proclaims:

The equation between the Christian Sunday and the pagan Thursday as the day in the week dedicated to the Lord and the day in the week dedicated to Jupiter, respectively, could not be expressed in a clearer manner. This passage corroborates the assumption that the objects of Caesarius’ criticism are some members of his diocese, that is, Christians who impiously treated Thursday as Sunday (… ne inter paganos magis quam inter christianos a Domino iudicetur). In Sermon 52.2, Caesarius associates the practice of Thursday-rest with various traditional beliefs of an astrological and calendrical nature — the latter referring to the observance of auspicious and inauspicious days in the Roman year —Footnote ¹⁶, and insists:

A few decades later, Martin, who from around 550 to 580 was bishop of Bracara Augusta in Galicia (present Braga in northwestern Portugal), addressed similar issues in a sermon that subsequently became known as a separate treatise titled De correctione rusticorum (On the correction or castigation of peasants). This work, composed around 574, is clearly influenced by the sermons of Caesarius of Arles (Barlow, Reference Barlow1950: 183–203; Hillgarth, Reference Hillgarth1969: 55–63; Reference Hilligarth and James1980).Footnote ¹⁸ In his treatise, Martin seeks to prohibit country-dwellers from engaging in a wide range of ‘pagan’ practices, including the habit of naming the days of the week after the planetary gods of the Greco-Roman pantheon and the habit of observing propitious days of the week to perform specific activities.Footnote ¹⁹ When dealing with Christian Sunday-keeping, Martin mentions the pagan practice of honouring Jupiter by observing Thursday as a day free of work (c. 18):Footnote ²⁰

In this passage Martin undoubtedly drew from Caesarius’ writings (in particular, from Sermons 13.5, 19.4 and 52.2). However, Martin's perspective appears to be slightly different from that of Caesarius: while the latter, as seen earlier, addresses and reproaches some members of his Christian community who sacrilegiously observe a Thursday-rest in honour of Jupiter at the expense of the Christian Sunday, Martin does not directly criticize Christian peasants in his diocese but rather warns them that keeping Thursday (instead of Sunday) by abstaining from work is a distinctly pagan custom that implies the worship of Jupiter, the supreme god of the Roman pantheon.

Going back to Gaul, after Caesarius, later in the sixth century, the ecclesiastical authorities were apparently still concerned about Christians observing Jupiter's Day by abstaining from work. Indeed, next to the recommendation that ‘nobody, neither a free man, nor a slave, nor a Goth, nor a Roman, nor a Syrian, nor a Greek, nor a Jew, shall carry out any kind of work on the Lord's Day’ (c. 13.3. Migne, PL 84. 611), the fifteenth canon of the Council of Narbonne of the year 589 reveals (c. 13.6. Migne, PL 84. 613):

This is a particularly valuable piece of evidence: although Gallic church councils are far from being unproblematic sources as to their interpretation (Bailey, Reference Bailey2016: 10–11), there is no reason to doubt that most of them addressed ‘specific problems experienced at the particular time and in the particular place where they were issued’ (Filotas, Reference Filotas2005: 52).Footnote ²² Furthermore, even assuming that church canons repeated issues and rulings over a long period of time, the fifteenth canon of the Council of Narbonne would still suggest that sometime before the year 589 a certain number of people in Gaul did keep Jupiter's Day. Even so, it is not possible to establish how many people observed a Thursday rest and when precisely such practice was in place.

While not directly mentioning the observance of dies Iovis further canons of Gallic councils of the sixth and seventh centuries repeatedly condemn any kind of work performed on Sunday.Footnote ²³ The observance of Christian holy days, especially Sunday, recurs in the work of Gregory of Tours, the Gallo-Roman historian and bishop who lived in northern Gaul during the second half of the sixth century (see Wood, Reference Wood1994; Heinzelmann, Reference Heinzelmann2001; Mitchell and Wood, Reference Mitchell and Wood2002). About twenty anecdotes in his Miracula record the dreadful effects of working on Sundays or on other Christian festivals.Footnote ²⁴ In addition, in a chapter of his History of the Franks (1.23), Gregory stresses that Christ rose again on a Sunday, in opposition to those who regarded Easter day as the Sabbath.

All these sources seemingly signal ‘a period of considerable concern over Sunday observance on the part of churchmen’ (Wood, Reference Wood and Baker1979: 64). It appears as though at the turn from late antiquity to the Middle Ages the Christian Sunday managed with some difficulty to reach its special position in the weekly cycle (Veit, Reference Veit1936: 134; Schreiber Reference Schreiber1959: 55). Apparently, the Christian Lord's Day had to compete not only with the Saturday of Jewish origin but also with the pagan Thursday. We should probably refrain, however, from overestimating the problem of Sunday observance in sixth-century Gaul. Judging from the available sources, it appears likely that compliance with Sunday keeping was generally the norm, while deviance from it presumably involved a small portion of the population (Wood, Reference Wood and Baker1979: 64).

An indirect allusion to the sacred character of Thursday can possibly be detected in the Liber Pontificalis, a book of biographies of popes from Saint Peter to the fifteenth century, whose initial version was probably compiled in the sixth century (Duchesne, Reference Duchesne1955–8).Footnote ²⁵ The chapter on Pope Miltiades, who occupied the Holy See in the early fourth century (311–14), reports as follows (LP 33): ‘He decreed that none of the faithful should on any account fast on the Lord's Day or on the fifth feria, because the pagans kept those days as holy fast’.Footnote ²⁶ As Duchesne (Reference Duchesne1955–8) pointed out, the reason provided for Miltiades’ decision regarding fasting on Sunday and Thursday is hardly credible. There is no evidence of any pagan fasts on specific days of the week. Since the chapter continues by stating that Miltiades ‘discovered Manicheans in the city’, it appears likely that this passage reflects some confusion between pagan and Manichean observances. As there is no hint of a second weekly fast as part of Manichean practices other than the one on Sunday (Duchesne Reference Duchesne1955–8: I, 169),Footnote ²⁷ it could be thought that two distinct elements relating to two separate traditions, that is, the Sunday fast of Manicheans and the pagan Thursday ‘sacredness’, were mistakenly conflated in the chapter on Pope Miltiades in the Liber Pontificalis.

Moving on to the mid-seventh century, we find a further reference to the Thursday-rest in the Life of Saint Eligius (Migne, PL 87.477–594; MGH SRM 4: 663–741; Head, Reference Head2001: 137–68). Eligius became bishop of Noyon in northern Gaul in 640 and was apparently a very active preacher in his diocese. In a passage of his biography, which allegedly gives a sample of his sermons and includes his attack of various pagan practices and superstitions, he is reported to have urged (PL 87.528; MGH SRM 4: 706):

It is generally agreed that although the Vita Eligii was originally composed by Eligius’ friend and contemporary Saint Owen around the years 673–5, most of the work is in fact not authentic. The biography has apparently come down to us in the form of a revised version of the Carolingian period, which, however, probably preserves sections of the original work. It has therefore been argued that the themes of this sermon reflect the concerns of the early to mid-eighth century, rather than those of Eligius’ time (Markus, Reference Markus1990: 209–10; Reference Markus, Fontaine and Hillgarth1992: 167; Head, Reference Head2001: 139; Hen, Reference Hen, Cohen and de Jong2001: 39–40). It is also widely acknowledged that the chapter of the Vita Eligii that includes the passage mentioned above was largely modelled on the sermons of Caesarius of Arles, as well as on Martin of Braga's De correctione rusticorum (Markus, Reference Markus1990: 209–10; Reference Markus, Fontaine and Hillgarth1992: 166–7; Banniard, Reference Banniard, Fontaine and Hillgarth1992: 73; Hen, Reference Hen, Cohen and de Jong2001: 39–40).Footnote ²⁹ As such, the work can hardly be regarded as an accurate reflection of paganism in seventh- or eighth-century Gaul. However, it is conceivable to assume that the Vita witnesses the fortune of traditions and practices of the pagan past in the Roman provinces of Gaul and Germany. Among these traditions and practices was the observance of dies Iovis/Thursday as a day of rest, although nothing is known of when such practice was in use.

The Homilia de sacrilegiis, ascribed approximately to the same epoch as the Vita Eligii, returns to the idea that whoever observes dies Iovis as a day of rest in honour of Jupiter is not a Christian but a pagan (c. 12; Caspari, Reference Caspari1886: 8):

This passage shows close similarities to a number of excerpts from Caesarius’ sermons, some of which have been examined earlier: both Caesarius (Sermon 193.4) and the Homilia list the seven planetary gods in week order (from Sun/Sunday to Saturn/Saturday), thus referring to what I earlier characterized as beliefs of calendrical nature, as well as to astrological beliefs associated more specifically with the gods of the planetary week;Footnote ³¹ both assert that work is not being performed on Thursday in celebration of Jupiter; both, finally, declare that whoever observes the Thursday-rest is regarded (by God as well as, presumably, by other members of their Christian community) as a pagan rather than a Christian.

Analogous ideas are found again in the eighth-century Indiculus superstitionum et paganiarum (‘A short list of superstitions and pagan practices’) (Homann, Reference Homann1965; Hen, Reference Hen and Collins2015: 183–8), as well as, subsequently, in further Christian homilies and penitentials, such as the penitential composed around 740, possibly by Archbishop Ecgbert of York (8.4): ‘…to observe the fifth feria in honour of Jupiter, or the calends of January, according to the pagan tradition’.Footnote ³² More recent penitential books suggest that the memory of the pagan observance of Thursday survived for a long period. For instance, the Corrector sive medicus, written around 1000 by Burchard, bishop of Worms, and widely used as a penitential book, asks such questions as (c. 92): ‘Did you make diabolic amulets … did you observe the fifth feria in honour of Jupiter?’Footnote ³³

It is unquestionable that these late antique and early medieval texts cannot be taken indiscriminately as descriptive accounts of contemporary non-Christian religious practice, or of ‘pagan survivals within the Church’ (Brown, Reference Brown2003: 153).Footnote ³⁴ This does not mean, however, that each and every reference to pagan customs in ecclesiastical sources should necessarily be regarded as a Christian creation of paganism, as is illustrated, for instance, by the case of the festival of the kalendae Ianuariae (on which see Meslin, Reference Meslin1970; Graf, Reference Graf and Graf1998; Lim, Reference Lim, Bowersock, Brown and Grabar1999). On the other hand, even in such cases where practices of the past clearly persisted into Christian times, these can be defined as distinctly pagan in their original forms, but not necessarily in subsequent periods. Of the sources considered above, the fifteenth canon of the Council of Narbonne is the one that is most likely to be genuinely implying that the weekly celebration of Jupiter's Day represented a real problem for ecclesiastical authorities sometime in late antique Gaul, although such deviant behaviour cannot be dated precisely and its scope is ultimately unknown. Even assuming that every reference to the Thursday observance in the sixth and later centuries was in fact a mere reiteration of sections of earlier ecclesiastical writings, thus devoid of any actual resemblance to contemporary local behaviour, it is nevertheless plausible to suppose that this repetition originated from a practice that existed sometime in the pagan past.

III. ZEUS’ DAY IN LATE ROMAN EGYPT

In an attempt to substantiate the assumption that during the Roman imperial period Thursday was kept as the most important and sacred day in the Roman seven-day week and that perhaps it was even observed as a day of rest on a hebdomadal basis, we now move to late Roman Egypt. Three late third- and early fourth-century documents on papyrus from Oxyrhynchus raise the possibility that official business was regularly suspended on Thursdays during the period in question. The first papyrus (P.Oxy. LIV 3741) preserves part of an official daybook, possibly compiled by a logistes. Footnote ³⁵ The document has been attributed to the year 313 and more precisely (albeit tentatively) to the time span from 2 September to 7 October in that year.Footnote ³⁶ The dates on the daybook are expressed according to the Egyptian calendar and run from 6 Thoth (= 4 September) until 10 Phaophi (= 8 October). Beside each date, the functionary who drafted the daybook recorded any activity relating to his office that was performed on that day. The office in question was not particularly frenetic, judging by the frequency with which the business conducted is described as οὐδέν, ‘nothing’. Particularly significant for our present purpose is the regular occurrence of the entry Διός, ‘of Zeus’, every seven days: on 6, 13, 27 Thoth, and on 4 Phaophi (l. 13, 18, 36, 44).Footnote ³⁷ It is noteworthy that none of the days marked as Διός is characterized by any kind of activity — the space next to each of these four entries is consistently left blank. Since Διός can be understood as a short form for ἡμέρᾳ Διός, which corresponds to the Latin die Iovis, the regular occurrence of the entry every seven days could be interpreted as an indication that in the early fourth century official bureaux at Oxyrhynchus were kept closed on Thursdays.Footnote ³⁸ In the daybook, there is a clear distinction between the several occurrences of οὐδέν-days, when activity apparently could have been performed but it was not, and Διός-days, when no activity was scheduled.

A confirmation of the supposed holiday status of ἡμέρα Διός/Thursday at Oxyrhynchus in the late third and early fourth century may be provided by a second papyrus, a petition against a nomination as dekaprotos dating to 31 December 287 (POxy. XXII 2343).Footnote ³⁹ Lines 8–9 of the document refer:

Coles (Reference Coles1985: 113) assumes that the word ἱερομηνεία should be understood simply as ‘festival’;Footnote ⁴⁰ indeed, the term hieromenia was originally used to refer to the period of interruption of hostilities connected with the great athletic festivals, but already by the fourth century BC it came to identify any festival period during which the legal apparatus of the state was suspended (Caulfield, Estner and Stephens, Reference Caulfield, Estner and Stephens1989).Footnote ⁴¹ The later sense fits with the hypothesis that the term was used in our papyrus from Oxyrhynchus to express the fact that 2 Tybi was a day dedicated to Zeus on a weekly basis, that is, a Thursday. In other words, the assumption is that ἱερομηνία τοῦ Διός was used here as an alternative to the usual formula ἡμέρα Διός. This conjecture is supported not only by the parallel of official bureaux closing on Thursdays offered by POxy LIV 3741, the logistes daybook discussed above, but also by the fact that, as Coles (Reference Coles1985: 113) aptly summarizes, ‘Tybi 2, year 4 and 3 (see 14 init.), = 29 December 287. This was indeed a Thursday.’ According to this interpretation, the sense to be attributed to lines 8–9 of POxy. XXII 2343 is that being 2 Tybi a Thursday — a non-working day — the man who wrote the petition against a nomination as dekaprotos could not approach the prefect and had to wait until the next day.

Although its text is fragmentary and its interpretation is not unproblematic, a third document appears worth being brought into this discussion. POxy. LX 4075 is another logistes daybook, probably dating to 4 /13 June 318.Footnote ⁴² At the very beginning of what is preserved of its recto, it records:

In the light of what was suggested regarding the two papyri examined above, this entry of the logistes daybook could be taken to mean that on the 11th, since it was Thursday and hence the bureau was closed, the logistes did not conduct any activity. As in the other official daybook considered earlier, in this case too Thursday would be expressed solely by the word Διός, ‘of Zeus’, which implies ἡμέρα, ‘day’. In this context, it should be pointed out that in contrast to the pattern for the days of the week in the epigraphic and literary sources, where the word ἡμέρα (or Latin dies) regularly accompanies the planetary or numbered designation, the evidence from documentary papyri includes a number of cases where the word ἡμέρα is in fact omitted.Footnote ⁴³

Beyond what is suggested by the three documents just examined, the Oxyrhynchus papyri do not provide any further hint of a regular suspension of work on Thursdays during the later imperial period. My analysis of all documents from Oxyrhynchus which would count as official activity (such as replies to petitions, tax receipts, and any other document that emanated from a public bureau and was signed or approved by an official) has offered no conclusive evidence in this regard. It should be noted, however, that this is due in the first place to the inadequate number of precisely dated documents among this specific type of material. As a result, it was not possible to determine what the pattern was — if any — in terms of the days of the week on which these official activities were performed.

Supposing that Jupiter's Day was a hebdomadal day of rest at Oxyrhynchus before Constantine's formalization of the Christian Sunday as a non-working day in 321,Footnote ⁴⁴ it still remains unclear whether Thursday was a holiday for the entire population or only for administrative and judiciary officials. Moreover, the extant sources do not allow us to determine whether the alleged status of Thursday as a non-working day would have been limited to the Oxyrhynchite or if it applied to the whole of Egypt, or perhaps to further regions of the Empire.