As we live, we’re aware of the fact of the passage of time. The sun rises and sets, and we experience a day. An easy sundial can measure the passage of a day and will be used to create sub-divisions of it. To complicate things, though, the sun’s altitude within the sky decreases at higher latitudes, which produces longer shadows than at lower latitudes, so the performance of sundials shouldn’t be uniform. On top of this, we all know that a day shouldn’t be of uniform length. For, as we recurrently experience the lengthening and the shortening of days, we mark the passage of a 12 months as measured by this basic solar experience.
The phases of the moon change the looks of the night sky across a lunar month, and this too will be used to mark the passage of time. In this manner, the lunar experience is added to the solar experience. But it really works to a special cycle.
Prehistoric stone alignments (akin to Avebury, Stonehenge and others within the UK and globally) appear aligned on the various positions of the sun and/or moon (for instance summer sunrise, winter moonrise etc) at different times of the 12 months. In that sense they seem like calendrical and were almost actually connected to seasonal ceremonies and agricultural activities.
Then there are stellar patterns, as stars appear in numerous parts of the sky at different times of the 12 months. This was observed by people from the earliest times and possibly used to mark seasonality and cultural events. The oldest image of a star pattern is considered that found carved on a bit of mammoth tusk dating from circa 30,500 BC. It is assumed to indicate the constellation of Orion. Babylonian records of observations of heavenly events date back to circa 1,600 BC. Some prehistoric stone alignments could also be connected to changing star patterns within the night sky. The Borana people of East Africa later based a fancy calendar on observations of the star clusters near ‘Orion’s belt’.
The seasons roll on their annual course: winter, spring, summer, autumn. The last of the leaves fall, frost occurs, and we realise winter has began again. Another 12 months has passed. Well, at the least that’s the seasonal cycle within the northern hemisphere. It is, after all, different within the southern hemisphere however the annual cycle can still be observed.
In other parts of the world the natural seasonal cycle is different; it might be roughly pronounced, but individuals are still aware of the passage of time across the 12 months. And other natural cycles occur too. The monsoon begins and ends; and a yearly cycle passes over again as measured by its winds and rainfall. Then there are seasonal flowerings of plants and migrations of birds and animals. However, it ought to be noted that just what number of ‘seasons’ a 12 months is split into is a human construction based on dividing up the phases of natural phenomena. Plus, all of us see (and feel) human life alter over time. Babies grow. All of us age!
In short, the passage of time is hardwired into our existence and our experience. But how we measure it’s a reasonably different matter. The units we decide are variable across history and cultures. And the differences noted within the solar and lunar cycles remind us that, even within the natural world, the passage of time shouldn’t be uniformly experienced in natural phenomena.
At the beginning of a latest 12 months, we turn out to be increasingly aware of the marking of time into significant chunks and milestones. Yet, we ceaselessly take with no consideration the milestones which are utilized by our own culture. A temporary take a look at a few of these will soon remind us of how variable these are and of how they’re rooted in numerous historical experiences.
How to divide a day?
The natural cycle dictates a day. But it doesn’t resolve how we culturally demarcate its passage. In Judaism the following day starts at sundown, not in the course of the night. So, what’s the evening of ‘Day A’ in communities influenced by Western Christian culture (which moved away from Jewish day-divisions) is early in ‘Day B’ in Jewish reckoning. Consequently, it was essential that Jesus be buried before nightfall on what English-speaking Christians later called a ‘Friday,’ because that was when the following day – Sabbath – began, on what English-speaking Christians later called, a Saturday.
The concept of a 24-hour day appears to be rooted within the Egyptian New Kingdom (1,550 to 1,070 BC), although hours were of various lengths. The Greek astronomer Hipparchus (died after 127 BC) later contributed to the 24-hour day idea, although the thirteenth century Islamic scholar, Abū al-Ḥasan al-Marrakushi, is commonly credited with introducing the thought of equal-length hours of the day.
We have noted Babylonian records of patterns within the sky. This was later built into divisions that influence common timing and calendrical divisions still used today. As the number 60 has many divisors, this seems to have led to their decision to adopt 360 days because the length of the 12 months and it was connected to the undeniable fact that the sun moves through the sky, relative to fixed stars, at about 1 degree of movement every day. The Babylonian base-60 fraction system continues to tell divisions of degrees, hours, minutes and seconds. This was since it is simpler to calculate with than the choice fractions which were utilized in Ancient Egypt and Ancient Greece.
What makes per week?
Most of the world – as a result of the globalisation that has occurred over the past three centuries – now operates on per week lasting seven days. However, earlier cultures had different lengths of weeks. These included a 10-day week in Ancient Egypt and an eight-day week utilized by Etruscans in Italy. Early Romans adopted this last pattern but, by the 4th century AD, were moving to a 7-day week under Christian influence. This, after all, was based on Jewish culture. In AD 321, Emperor Constantine decreed a seven-day week within the Roman Empire. This included making Sunday a public holiday.
The seven-day week had an interesting history. We have already noted its importance in Judaism, where the creation story in Genesis pictured God creating over six days and declaring the seventh day a ‘day of rest’ – the Jewish Sabbath (Shabbat). This was (and is) on the day of the week before the one marked as such by Christians. It is a reminder that the resurrection of Jesus occurred on the primary day of the working week in Judaism. This then became, for Christians, the ‘day of rest’. This is an example of how the importance of the passage of time is culturally decided and may change over time. Islam also works on a seven-day week but with the ‘day of congregation’ (yaum al-jum’ah) being on a Friday.
Other ancient Middle Eastern cultures (recorded way back to King Sargon of Akkad, in circa 2,300 BC) venerated the number seven as a time-period division.
What really constitutes a 12 months?
We have seen how the Babylonians had a 12 months of 360 days. The Babylonians also devised a 12 months of 12 months, with every month made up of 30 days.
An analogous, Chinese, pattern of a 12-month-year, with the occasional occurrence of a thirteenth month, will be dated to circa 2000 BC. However, a calendar of three hundred and sixty six days (based on the movements of the sun and moon) will be identified from circa 3,000 BC in China. But there was an issue. The Chinese were aware that this was not accurate and, by the 2nd century AD, realised it became unreliable over 300 years.
The problem is rooted in a phenomenon called ‘precession’. This is the gradual movement of the Earth’s rotational axis in a circle relative to the fixed stars. It signifies that the length of the 12 months shouldn’t be actually a set time frame. This was recognised by astronomers over 2,000 years ago.
The very early Romans (they of the eight-day week) originally had a 10-month 12 months. That is why their names for September, October, November and December indicate that they’re the seventh, eighth (think eight-armed octopus), ninth and tenth months, once they are actually the ninth, tenth, eleventh and twelfth months in a 12-month 12 months. Incidentally, the Romans expanded to a 12-month 12 months as early as 713 BC but since their 12 months began in March the old names still worked. The 12 months lasted 355 days. However, they knew there was an issue and later, every two or three years, would deploy an additional month.
Political considerations (‘Is a shorter or longer 12 months politically useful right away?!’) meant this was poorly applied. By the center of the first century BC the official calendar was getting well out of sync with the fact of the seasons! To cut an extended story short, Julius Caesar took on board Egyptian calculations, the result being a 12 months of three hundred and sixty five days, with an additional day added to every year that was divisible by 4 (because a solar 12 months was calculated as lasting 365 and 1 / 4 days). This became generally known as the ‘Julian Calendar’.
Problem sorted. Well, no. The ‘Julian Calendar’ assumes that a solar 12 months lasts 365.25 days. However, it actually lasts 365.24219 days! The difference slowly causes administrative problems over time. In the 4th century AD the – newly Christianising – Empire decided that Easter Sunday would fall on the primary Sunday, after the primary full moon after the spring equinox (when the hours of day and night are equal). This last event was tricky to calculate, so it was decided that it might be on 21 March every year. Over time, this date fell later and later within the 12 months, in comparison with what it had done back within the time of Julius Caesar. If nothing was done about this, Easter would eventually fall within the early summer (clearly at odds with its springtime setting).
In 1582, Pope Gregory XIII acted. The calendar was reset: October that 12 months lost 10 days; after 1600 no 12 months exactly divisible by 100 could be a bissextile year (except when it was divisible by 400). For those reading this and (like me) wishing they’d concentrated more in maths lessons, suffice it to say that it (principally) fixed the issue! This is the ‘Gregorian Calendar.
Problem finally sorted? Well, type of! Due to it being devised by a pope, many Protestant and Eastern churches were reluctant to adopt it. It was not until 1752 that the UK finally brought its calendar into line with the Gregorian system, by taking 11 days out of September that 12 months, after which – thereafter – following the ‘Gregorian Calendar’. Others stood out longer. Russia, for instance, didn’t change until after the 1917 Revolution. Consequently, the Bolshevik ‘October Revolution,’ took place on 7 November 1917 in the fashionable calendar! That is why some UK school history textbooks date it to that month, whereas no tractor factory within the USSR was ever named ‘Red November’!
The law which modified the UK to the ‘Gregorian Calendar’ also decided that 1752 would start on 1 January. Before that, years were reckoned in lots of Western Christian nations to start out on 25 March (‘Lady Day,’ the date decided in medieval times because the ‘Feast of the Annunciation’). Until then the UK Tax Year began the day after: 26 March. In 1758, the 11-day change of 1752 was applied to it as well and moved it to six April. It has remained there ever since. That is why the UK Tax Year doesn’t start on 1 January!
Synchronise watches!
Today we take accurate measurement of time with no consideration. And we assume uniformity of it inside demarcated time zones. But these – while rooted in the fact of the movement of the earth – are still artificial constructions. We within the UK and the Republic of Ireland are members of 1 time zone. However, the sun doesn’t know that. For example, before the nineteenth century, ‘Local-Time’ (originally based on local sundials) across Britain varied: ‘Oxford Time’ was 5 minutes behind ‘Greenwich Time’ (ie ‘London Time’), ‘Bristol Time’ was 10 minutes behind, and ‘Exeter Time’ was 14 minutes behind it. Try running a railway on that system!
In November 1840, the Great Western Railway in England established a single standard time across its network. By 1855, ‘Railway Time’ (which was ‘London Time’) was communicated by the brand new telegraph system. Before that, train guards passed on the time from Paddington across the system. By 1855, 98 per cent of towns and cities within the UK had transferred to ‘London Time’. But there was resistance! Public clocks in Exeter, for instance, continued to indicate ‘Local Time’ and only revealed ‘London Time’ (14 minutes ahead) via a second hand added to the clocks! This was as a result of the reluctance of the Dean of Exeter Cathedral to provide in to the railway firms; and so the cathedral clock resolutely showed the local time. It was not until 1880 that an act of parliament established uniform time across the entire of Britain.
As we start this latest 12 months, spare a thought for the millennia of historical calculations that lie behind these (apparently) straightforward actions. Happy New Year!
Martyn Whittock is a historian and a Licensed Lay Minister within the Church of England. The writer, or co-author, of fifty-six books, his work covers a big selection of historical and theological themes. In addition, as a commentator and columnist, he has written for several print and online news platforms and been interviewed on TV and radio news and discussion programmes exploring the interaction of religion and politics. These have included being interviewed on news platforms in regards to the religious dimension to current US politics, Christianity and the Crown within the UK, and the war in Ukraine. His most up-to-date books include: Trump and the Puritans (2020), The Secret History of Soviet Russia’s Police State (2020), Daughters of Eve (2021), Jesus the Unauthorized Biography (2021), The End Times, Again? (2021), The Story of the Cross (2021), Apocalyptic Politics (2022), and American Vikings (2023).
