See caption
William Lilly was one the best-known writers of astrological almanacs in 17th-century England
Source: Wikimedia Commons

Egyptian days, also known as Dismal days after the Latin dies mali (“evil days”), are days of the year that are considered to be unlucky to carry out any important undertaking such as getting married or travelling. Such lists of days had been known in Anglo-Saxon England, but it was not until the 16th century that they started to be based on astrological calculations, becoming so popular in England that almanacs containing such prognostications were even outselling the Bible by the mid-17th century.[1]

There is no plausible explanation for why Egyptian days were so named, but suggestions have included that they were first computed by Egyptian astrologers, or may correspond to the dates of the Biblical plagues that affected ancient Egypt.[2]

Certainly Egyptian astrologers did produce lists of inauspicious days, two in each month, the most potentially harmful of which were said to correspond to the last Monday of April, the second Monday of August, and the third Monday of December, in our modern calendar.[3][a]The Ancient Egyptian calendar consisted of a year of 365 days divided into 12 months of 30 days each; an additional 5 days were added on at the end of each year, but were not considered to be part of the year. The Romans had similar days they called deis nefastus (“unlawful days”), on which no public business was to be transacted.[4]

English astrological almanacs

Various translations of continental prognostication had long been been in circulation in England, but it was not until 1545 that Andrew Boorde, an ex-Carthusian monk, produced the first English almanac. By the end of the 16th century more than 600 almanacs had been published, and it has been estimated that more than 2000 were issued in the following century. William Lilly’s Merlinus Anglicanus alone was selling 30,000 copies a year by 1649. The standard price of an almanac in the 17th century was two pence.[5][b]Two pence in the mid-17th century is the equivalent of about £18 when comparing average earnings with 2017.[6]

There appears to have been no general agreement about how to calculate the Egyptian days, as the dates published in various almanacs rarely agreed with one another.[7]

Contemporary scepticism

There were several mock almanacs that poked fun at the ambiguous hedging of the prognostications of the astrological almanacs with many “ifs” and “buts”, some of which were almost as popular as the real thing. In its predictions for February 1664 Poor Robin stated that “We may expect some showers or rain either this month or the next, or the next after that, or else we shall have a very dry spring”. In addition it was claimed that what the astrologer William Lilly called judicial astrology could only consider natural causes, not God’s miracles such as Noah’s Floods. Thus Vincent Wing, in his prognostications for 1647, concluded with the remark that “the Almighty [might] dispose otherwise and so frustrate the portents of Heaven”. Another common excuse astrologers produced for their failures was errors in their calculations.[8]

Attitude of the Church

The medieval Church had battled against what it regarded as the superstition of Egyptian days but with limited success, at least partly owing to the apparently similar vagaries of its own liturgical year. Every day had been given some symbolic significance, added to which were seasonal taboos and observances such as abstention from meat on Fridays and during Lent. Saints’ days in particular had a “supernatural aura”; a sin committed on a saints day was considered more serious than one committed on any other day of the year. Friday was considered to be particularly unlucky, as it was the day of Christ’s crucifixion. Thus the Church essentially reinforced the idea of the unevenness of time underlying the notion of Egyptian days, rather than arguing effectively against it.[9]




Dent, S., editor. “Egyptian Days.” Brewer’s Dictionary of Phrase and Fable, Online, Chambers Harrap, 2012.
MeasuringWorth. Five Ways to Compute the Relative Value of a UK Pound Amount, 1270 to Present. 2020,
Staff writer. “Egyptian Days.” Holidays, Festivals, and Celebrations of the World, edited by Helene Henderson, 5th ed., Omnigraphics, 2015.
Thomas, Keith. Religion and the Decline of Magic: Studies in Popular Beliefs in Sixteenth and Seventeenth-Century England. Ebook, Penguin, 2003.