The medieval calendar in May

Trinity College Library, Cambridge – Labours of the Month – May

Time flies when you have your head down and are typing manically. Since I last posted I’ve been banished from court, gone on an adventure to the West Indies and am now absconding to Tuscany via Naples having deserted a wife and five children under the age of eight. I’ve built a galleon and pinnace and my Italian has improved – no seriously, my Italian really has improved. My only problem is that it relates to ship building and piracy and neither of those two options are something I would consider to be part of a lovely holiday. However it has finally dawned on me that despite the weather here it is May – so time for an occasional calendar post. Normal service will resume this week.

May – time for a spot of falconry or courtly love. I’m not sure whether either one of them counts as a labour. The Book of St Albans (1486) lists the kind of bird of prey that you would be allowed according to your rank. Emperors can fly eagles whilst knaves can fly kestrels – hence the book title. It was a bit of an extravagant way of labouring for food.

Unsurprisingly Henry VIII’s book of hours is about courtly love but also contains images for the two star signs of the month – Taurus and Gemini.

Morgan Library MS H.8, fols. 2v–3r  April and May. Houses of Henry VIII

February, blood letting and monasticism

Today I’m combining February’s calendar page information (yes, I know its the middle fo the month) with monasticism. Bloodletting was an important part of medieval health. If you were a monk you would pop along to the warming-house/room, usually in the late morning or early afternoon having had a snack in the refectory first. Monastic blood letting seems to have been akin to letting a vampire do his worst because accounts suggest that monks might lose up to four pints of blood during a letting. In fact monks were so weakened by the experience that they needed to spend time recuperating without the requirement for labour and with a relaxed dietary regime. On the third day after the bloodletting, the monk joined the rest of the community for some of the offices and might start doing a spot of light reading.  

Monks, certainly Cistercians, were bled four times a year including February. Basically the idea was that blood letting was a restorative that sharpened the mind and quenched the kind of urges that might get monks into trouble. If the truth was told the quarterly blood letting probably meant that the monks had more blood taken than they had baths each year.

The ‘vein man’ – a guide to blood letting. Wellcome Images L0020781

Candlemas on the 2nd of February ended the Medieval Christmas cycle. It was also often depicted as a time to rest – there are many images of agricultural labourers toasting their feet and warming their hands in front of a roaring fire in February.

The astronomical signs for the month began with Aquarius and ended the month with Pisces. Books of hours contained the astrological symbol for each month because it helped decide on medical practices – so letting blood from mid January to mid February was good because it is good to do things that last only a short while under Aquarius. But once the star sign changed it wasn’t a good idea to have anything medical done to your feet- not sure where you stand on clipping your toe nails as my medieval medical understanding isn’t that well defined.

In fact whilst we’re on the subject of blood letting – it depended on the month as to where blood should be taken and also what condition it was good for.

An example of the ‘theory’ of melothesia in which a particular parts of the body are associated with zodiac symbols. WI no. L0047652

There is a name for the way in which parts of the body are associated with different zodiac symbols – melothesia – if you please. It had a Babylonian background so we are back to the transference of knowledge via the Arab world.

Try this link for more information about health care and monasticism:

Medieval calendar – January

British Library – calendar page for January  ‘Isabella Breviary’ (Add MS 18851)

This calendar was created for Isabella of Castile in the 1480s.

Remember medieval calendars are perpetual.

The Roman numerals or golden numbers on the left hand side of the page tells you when the new moon will appear and logically when 14 days later the full moon will appear. The numbers are from 1 to 19 and represent the metonic cycle.

Thus you need to know where you are in the 19 year cycle to work out which of the 19 numbers is the new moon fo 4th year you happen to find yourself in.

The metonic cycle basically works on the premise that across a period of 19 years there are approximately 235 lunar cycles after which the cycle will repeat itself on the same day ie the moon will be in the same place in the sky with the same stars. The cycle was discovered by the Ancient Greeks.

The golden number of any calendar year (Julian or Gregorian) can be worked out by dividing the year by 19. Now add 1 to the remainder, and that number is the golden number for the year. 


2021 divided by 19 = 106 remainder 7

7 + 1 = 8. So in 2021 the Roman number 8 will provide the day in the metonic cycle on which a new moon appears. Of course you’d need to know which days fell where within the cycle to do the calculation. Then it’s a question of counting on 14 days to calculate the full moon. This was important for working out when Easter would fall in any given year (the first full moon after the Spring equinox.) Across the metonic cycle Easter could only happen on 19 specific dates and if you knew where you were within the cycle you could calculate this.

Calculating the golden number for any given year. table to work out when the new moon would fall in any given month using the golden number.

2021 is the eighth year of the metonic cycle but applying the medieval perpetual calculator to work out the date of the new moon in 2021 won’t work because of the drift in the Julian calendar – when we changed to the Gregorian calendar we lost 10 days! The first new moon of 2021 falls at about 5.00am on January 13th and is apparently a wolf moon whereas the Golden Numeral method of calculation states that the new moon falls on the 6th…which is clearly not correct!

The calendar page for January often depicts Aquarius- usually a bloke pouring water from a downturned jug. There may sometimes be an image of Janus – the two-headed god after whom January is named looking towards the future and back towards the past.

The main agricultural/seasonal illustration is often a winter scene or someone warming themselves by the fire as above.

The British Library has a lot of useful information on medieval calendars.

dies Aegyptiaci – Egyptian Days – calamitous dates for the diary

Calendar pages for November, from the Hours of Joanna of Castile, Netherlands (Bruges), between 1496 and 1506, Additional 18852, ff. 11v-12

My head is full of bees and they’re quite happy buzzing around. As a result of the Zoom session which involved an understanding of medieval calendars I have a new bee buzzing gently at the back of my skull! Medieval calendars.

Egyptian Days, of which there were 24 each year, were the days that medieval calendar users believed to have been identified by ancient Egyptian astrologers as unlucky for new projects, battles, setting off on journeys, business deals and also for blood letting amongst other things. Apparently no self-respecting Anglo-Saxon would have eaten a goose on an Egyptian Day. The other way of describing them was as “evil days” which translated from Latin gives us the word “dismal.” And I’m very sorry if your birthday happens to fall on one of the days listed below. It was considered an unlucky start in life.

January 1st and 25th

February 1st and 26th

March 1st and 28th

April 10th and 20th

May 3rd and 25th

June 10th and 16th

July 13th and 22nd

August 1st and 30th

September 3rd and 21st

October 3rd and 22nd

November 5th and 28th

December 7th and 22nd

As with all these things there were those who dismissed bad luck days as superstitious nonsense, one such was the chronicler William of Newburgh who thought they were nonsense – unless you happened to be Jewish in which case England was to the medieval Jewish community what Egypt had once been which accounted for the murder of the Jewish community in York to to mention associated anti-jewish rioting and it was all down to Egyptian days rather than any unpleasantness by the local population.

As if that wasn’t bad enough there were plenty of medieval calendars that also incorporated dangerous hours. By the fourteenth century not only should you have your blood taken from an auspicious location according to the planets but you also had to watch out which day it was and what the time might be.

Egyptian Days can be found at the top of medieval monthly calendars and marked with a letter “D” for evil days.

SKEMER, DON C. “‘ARMIS GUNFE’: REMEMBERING EGYPTIAN DAYS.” Traditio, vol. 65, 2010, pp. 75–106. JSTOR, Accessed 3 Nov. 2020.