New Year’s Day, Calendar Years, and the British Tax Year


January 1st has been known as New Year’s Day since the Roman times. But that didn’t necessarily mean it was the first day of the new year. Different countries and even different regions of countries celebrated the beginning of the year on various dates: Two common dates were March 25 and December 25. But let’s see how this all played out for Britain…

Julian Calendar

In 46 BCE Julius Caesar gathered together his best astronomers and mathematicians in Rome to design a new calendar. He modestly called it the Julian calendar after himself. It set out the first day of the year as January 1, and it did a pretty good job of keeping track of all the days and months.

However, there was a small miscalculation of 11 minutes per year. This doesn’t sound like much, but it added one extra day every 128 years. After being in use for a thousand years or so, the Julian calendar was getting off track and the months were starting to drift into the wrong seasons.

Julius Caesar calendar new year 700

Gregorian Calendar

In 1582 the Vatican stepped in to sort things out. They came up with a new calendar, called the Gregorian Calendar, after Pope Gregory XIII. It kept New Year’s Day as January 1 and put everything back in order. This new calendar was adopted by most of Europe, which was under the Pope’s authority.

England’s Having None of It

However, nearly 50 years earlier, King Henry VIII of England had thumbed his nose at the Pope and declared himself no longer under his control. So his Protestant daughter, now Queen Elizabeth I, wasn’t about to let Rome tell her what day it was. She was having none of this newfangled calendar.

Elizabeth calendar new year 700

So for 170 years Britain carried on with its old calendar, getting further and further out of sync with the rest of Europe. Business people who traded with others around the globe had to use both dates to avoid confusion.

By 1752 the British calendar was 11 days off. It was time for Britain to swallow its pride and conform. It adopted the Gregorian calendar in September 1752. But what to do with those 11 extra days?

Missing: 11 Days

They decided to just skip those pesky, surplus days. So everyone went to sleep on September 2, 1752 and woke up the next morning to September 14. To some people this was very disconcerting and they feared that they might be losing 11 days of their lives.

However, at least one man saw an opportunity to make some money out of these missing days. He bet anyone who would take the bait that he could dance nonstop for 12 days. Of course, that seemed impossible and he had a few takers. He waited until the evening of September 2. He began his little jig and danced all night long. When he stopped the next day, it was September 14 and he collected his money on a technicality.

British Tax Year

All this calendar confusion actually clears up something that I’ve wondered about since we moved to England several years ago: Why does the UK tax year start on April 6?


As it turns out, this odd date can be traced back to the “Great British Calendar Changeover.” Under the old Julian calendar, even though January 1 had been called New Year’s Day, both the civil year and tax year began on March 25. When the country changed to the Gregorian calendar, they also changed the first day of the year to January 1.

You Still Have to Pay Your Taxes

The government didn’t mind changing the start date of their civil year or losing 11 calendar days. However, they drew the line at the thought of a shortened tax year. So the Lords Commissioners of the Treasury decided not to align the tax year with the civil year. The old tax year was March 25 to March 24 and they just moved it up 11 days so they could get their full 365 days’ worth of taxes. This made the tax year April 5 to April 4.

This remained the British tax year until 1800. 1800 would have been a leap year under the old calendar, but was not one under the new calendar. Again, the Treasury wasn’t about to lose out on a day of tax collecting, so they moved the tax year one day ahead and this is where it has remained. Finally, the mystery of the April 6 to April 5 tax year is solved!

Here’s wishing you a very happy New Year – whenever you decide to celebrate it!

Read more stories like this in my book Bowlers, Brollies, and Brits: Curious Histories of England

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Margo Lestz


  1. Dear Margo

    You really do find the most fascinating things! Having lived in England in the 70s I knew they had this weird tax year, but didn’t do as you have done, and research it. Another thing with dates that had me totally puzzled was the change to BCE and CE. I finally realised it was done to remove the references to Christianity, which dated from the time of the Gregorian calendar. It is only in the modern world that the world has adopted the western Calendar – basically for commercial reasons. This might be another subject for you?

    I wish you a happy and healthy 2018.

    1. Thanks, Paula. The UK tax year has been a mystery to me for years. I just ran across this bit of info and now the mystery is solved. 🙂 Now on to the next one…
      Wishing you and yours a wonderful 2018!
      All the best,

  2. Margo,
    I am always amazed at what a smart woman you are! Ever since we met in high school you were curious and I am so glad that you have not lost that spirit of adventure and intrigue!
    Thanks for doing all of this research and making history come to life!

  3. Happy New Year!! 🎊🎉love and happiness, the very best for you and Jeff.
    with love,

    1. Hi Patricia. Happy New Year to you too! (And a belated Happy Birthday!) Wishing you and your family a wonderful year filled with amazing times! xx

  4. OH. I had always assumed that the taxable year and fiscal year dates were chosen based on such events as harvests and the traditions just continued to present regardless of the change in economic importance of agriculture. I grew up in the US with Apr. 15 always being the tax deadline, little did I know that was a fairly recent, historically speaking, date. Very interesting!

    1. Well, in the US, the tax year is the same as the calendar year (Jan 1 – Dec 31) with filing deadline on April 15.
      In the UK, the tax year is April 6 of one year through April 5th of the next with the filing deadline on December 1.
      It all gets very confusing when you have to do returns for both countries. 🙂

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