Celtic Timekeeping


Celts tracked the passage of days in terms of ‘nights’. But a Celtic 24-hour period seems to have begun and finished at the distinct marker that is ‘disappearance’ (sunset) rather than at the vague midnight as we now measure the change between days. Thus there was a ‘night’ followed by a ‘day’ and there seems to be little recorded evidence of specific time-keeping methods within that though it stands to reason that they would have tracked time by the position of the sun or moon overhead.

For defensive purposes (and Celts were warriors first and foremost) each ‘day’ had eight defensive watches of three hours each.

Midnight             22.30 – 01.30

Dawn                    01.30 – 04.30

Morning               04.30 – 07.30

Mist-rise              07.30 – 10.30

Midday                 10.30 – 13.30

Rest                      13.30 – 16.30

Dusk                     16.30 – 19.30

Disappearance   19.30 – 22.30

The most evocative watch is ‘mist rise’ which, in the language of the Gaulish Celts was ‘anthert’ or absence of vapour (an=absence of, thert [presumably] vapour or mist). I can well imagine the Celts pottering around until well into our morning waiting for the overnight mist to clear so they could go about their business.

The most intriguing is ‘rest’ (13.30-16.30) which seems both a long and ill-timed place to have a few hours off. I don’t think the times are indicative of a three-hour-long siesta (a tradition from Southern Europe) but rather the watch came to be named after a shorter period of rest that happened in the middle of the working day. Our phrase ‘noon’ which we apply to ‘midday’ comes from the Old English non which means ‘the ninth hour from (6am) sunrise’. Or 3pm. Smack in the middle of the (older) Celtic ‘rest’. Given the possible late start to the day waiting for the mist to clear, I think it’s possible that Celts worked through until stopping for a meal and a break around our 3pm and then perhaps resumed again until the light started to run out toward the end of ‘dusk’.

The passage of broader time across months and years were tracked by the movement of star constellations across the heavens and by the moon respectively. Therefore, Celts are believed to have had a lunar/solar calendar with a very straightforward (but effective) way of countering for seasonal ‘drift’. Check it out in these posts about the Coligny Calendar, the Celtic Week, Celtic Month and Celtic Year.

(Celtic) Coligny Calendar

The Celtic calendar has been estimated by scholars based (amongst other evidence) on the re-assembled remains of a 5ft wide, beaten copper, ‘perpetual’ calendar buried in the ground in Coligny, Gaul, to protect it after it was destroyed, probably by the Romans.

The Coligny calendar had little peg holes next to every single day which helped the Gaulish Celts track time across a fixed five year (60 month) period. It established a year of twelve months of 29 or 30 days with a leap month every 2.5 years to correct seasonal drift. While it seems fiddly to interject a whole month every 2.5 years it’s much simpler to think of it as every thirty months. Simpler still if you consider it as mid-way and end of the 60 month period. Suddenly it’s quite straight forward and must have made as much easy sense to the Celts as “thirty days has September, April, June, and November…” does to us.

The Coligny Calendar (photo: D. Bachmann - image is in the public domain).
The Celts were big on duality (things being either one thing or the other — dark time of year/light time of year, summer/winter, good/bad, day/night) and so it makes sense that they would divide their 60 month period into two halves and mark each with an extra month at its end. And depending on what the climate was doing that month would either have been extra harvest/work time or extra hunkering down/winter time.

To stop it slowly creeping too far the other way, every five ‘sets’ of 60 months (ie: every 30 Coligny years or 40 actual years) they would finish the period and NOT have the extra month, dragging it back by 30ish days. Those simple rules kept the Coligny Calendar (ie: the Celtic calendar) ticking along accurately and comparisons to the modern/Gregorian calendar certainly show it keeps admirable pace with our own sense of timekeeping.

Celtic Month

Experts are divided on what phase of the moon the Celts started their month. Modern, western society starts ours on the ‘new’ moon (when it’s fully dark). Some think the Celts started on the full moon because that’s when they celebrated festivals etc.

But Pliny the Elder (who, it must be said, captured many correct details of popular culture of his time but managed to either invent or misreport many others) wrote of the Celts beginning their month on ‘the fifth day of the moon’. This seems like a bit of a random time to start a month until you consider that it coincides with the quarter-moon, a phase in which the moon appears exactly half/half light and dark to us on Earth.



Half/half is a pretty unequivocal kind of shape (compared to the three-day linger of a new and full moon) because every eye turned to the sky could see when the moon was exactly divided (even one day before or after a quarter-moon is visibly not half/half). And it fits with the common Celtic practice of interpreting their world dualistically.

Starting the Celtic month at a quarter-moon ensures that the first fortnight is ‘light’ as the moon gets fuller and brighter, and that the fortnight following it is ‘dark’ as the moon goes back to being in shadow. In fact, the Celts seemed to call them a bright moon and dark moon respectively (rather than ‘full’ and ‘new’ which are contemporary terms). This fits with references in the Coligny Calendar to the Mat and Anmat periods in the first and second halves of the month. (mat meaning ‘light’, and an as we’ve seen elsewhere meaning absence of).

Therefore, if a month began on the quarter moon (half/half) then the mat fortnight would take us through the brightest part of the month, until the three-quarter moon (where the half/half is reversed) and then the period marked as Anmat would predominantly feature a dark moon. But… the Coligny Calendar clearly marks the second fortnight of each month with the Gaulish word Atenoux which has been translated as the return of light. The dark fortnight would most definitely end in the return of light. So perhaps the Atenoux fortnight was all about looking forward to the moon’s return.

Celtic Days, Weeks and Fortnights

Pre-Christian Celts counted the passage of time in nights (starting and finishing at sunset) rather than days, with longer periods being se’nnight (seven nights) and fortnights (forten-night or fourteen night).

The concept of fortnights is much older but the word itself comes from the Old English fēowertyne niht (fourteen nights). It has long outlasted its cousin ‘sennight’ which has fallen out of use now. 

Though neither word was actually used by Celts lingering in post Roman Wales (who would have had their own word for it), I’ve used it in y Ddraig so that it’s meaningful to readers (except for those in the US which is reportedly the only English-speaking country in the world not to use the term).