The Lady, the Pope and the Dwarf; the surprising history of why the UK tax year starts on 6 April

On this day in 1753, many honest, upright citizens of England and the British Empire began paying the taxes for the previous year. Such taxes were due on New Year’s Day (or the day after, the story is confused), and these worthies had refused, for 11 days, to pay up.
How so?

Prior to 1753, the legal year in England and beyond began on 25 March which they called ‘Lady Day’. This is the Feast of the Annunciation, when the angel Gabriel appeared to Mary, to tell her that she would conceive a child. Conveniently, this was exactly nine months before the Roman festival of Saturnalia, their celebration of the winter solstice, and well known for feasting, drinking and general debauchery. This festival could be very happily syncreted into Christmas.

New Year was more generally recognised on 1 January, and between then and Lady Day dates were often written as, for example, 1648/49 to avoid confusion. Charles I’s execution is noted in the official records as being on 30 January 1648; today we have changed this to 1649.

Lord Chesterfield’s Calendar (New Style) Act 1750 changed the date of the start of the legal year to 1 January. But it did more than this. It changed the English calendar from Julian to Gregorian, and it sorted out when Easter was.

In the middle of the first century BC, Julius Caesar recognised that the Roman calendar was out of synchronisation with the seasons. In part this was due to the consuls adding an ‘intercalated’ month more or less at will. Caesar, so the story goes, asked the Greek Cleopatra, his latest squeeze, to sort things out. And she got Sosigenes to calculate things. As the Greeks were accepted as being much cleverer than the Romans, Caesar accepted this.

However by the late 16th century, the calendar was again out of sync, particularly in relation to Easter. Easter is related to a full moon after the spring equinox; the calendar was then 10 days out, a serious theological problem. Pope Gregory XIII got his astronomers to recalculate the calendar. They did it using the Copernican heliocentric theory (naughty!), as it made the maths easier. The Gregorian calendar was introduced in 1582, effectively a 0.002% change in the length of a year. (Not bad for an ancient Greek, you might think.) We still use the idea of ‘intercalation’ in leap years, when February gains a day.

Much of Europe accepted the new calendar; in the protestant north it was resisted because of it’s ‘papist’ origin. By the mid-eighteenth century the differences in dates was seem to be hampering international trade, hence the impetus for change.

The Act organised the change, allowing how prison sentences were to be altered, and re-ordering almost everything else, but it seemingly didn’t realise that the tax-payers might resent paying tax on a full year 11 days early. The date change was between Wednesday 2 September 1752 which was followed by Thursday 14 September.

The calculation of the date of Easter was the most important one for the church. Dionysius Exiguus or ‘Dennis the Dwarf’ had worked out to calculate this around 525 AD, and his method was quickly adopted. Dennis was also responsible for the chronology we call BC and AD. However, in his time 0 (zero) was unknown in Europe; the year 1BC is immediately followed by 1AD.

The Anglican church also used Dennis’s calculation for the date of Easter, as modified by the Gregorian calendar, but preferring not to recognise the ‘papist’ origin produced its own method of determining this, as found in the Book of Common Prayer.

The delay in payment of taxes in 1753 was gradually accepted by the authorities, and legislated for in the early 19th century, and has been the start of the tax year ever since in the UK.