Tax year, 6 April – 5 April, why on earth?

What have the Romans ever done for us? Well, quite a lot, actually, with respect to our funny tax year. And it’s all to do with the switch from the Julian calendar (proposed by Julius Caesar in 46BC) to the Gregorian calendar in 1582.

Let us explain. After the switch was made, it was some time before scholars realised that the Julian calendar had been inaccurate to the tune of 9 solar days. But even back then, England, liking to buck the European trend, had stuck with the old regime until September 1752. And it was only at this point they discovered that another 2 days had been lost.

In a bid to right this shocking wrong, 2nd September was followed by 14th September that year. But to ensure the treasury still had enough coins coming in, the missing days were added to the end of the year. In the Middle Ages, because the legal year began on Lady Day (25th March), this meant the tax year switched to beginning 5th April. Then a little matter of a leap year adjustment was made in 1800, and hey presto! The new tax year became as we now know it; 6th April.