As you will be aware the tax year in the UK runs from 6th April to 5th April – but why such random dates?

It all dates back to Julius Caesar!

Back in 45 BC we used the Julian Calendar and New Year’s Day was officially 25th March.  However in the 16th century Pope Gregory Xiii decided that the ‘Julian’ calendar wasn’t accurate enough as it had lost 9 days since its introduction, compared to the solar calendar.

So with this in mind, Pope Gregory introduced the Gregorian calendar.

The Gregorian calendar reduced the length of the calendar year from 365.25 days to 365.2425, a reduction of 10 minutes 48 seconds per year!  This meant his calendar was a much more accurate time keeper.

At that point the Gregorian Calendar was introduced by many countries including Italy, Spain, Portugal and what was then the Polish-Lithuanian commonwealth. However the British Empire didn’t adopt it until 1752, by which point we were 11 days off the rest of Europe!

As the old New Year’s Day was 25th March and in order to avoid losing revenue the British Treasury decided that the tax year which started on 25th March 1752 would be the usual 365 days, thereby running until 5th April.

This ran smoothly and accurately until 1800, when a leap year hiccup meant that a day was lost and therefore the British Treasury once again moved the start of the tax year to 5th April and it has remained there ever since!

And who said accountancy was boring lol 😊