It was only a simple query in a school test - why does Britain's tax year start on April 5? But according to a recent report, the question took Britain's Inland Revenue's best minds a full seven years to answer. The saga started in 1965 when pupils at Longfield Church of England junior school in southern England were set an Easter holiday quiz, the Daily Telegraph said, citing newly-released government archives. Mark Meadcroft, aged 10, came up with an answer with the help of his father, who worked as a tax official. However this answer differed from that given by the headmaster, who asked Mr Meadcroft's father to look into it. The archives show that Aubrey Meadcroft's simple query to the Inland Revenue's librarian sparked years of research, including a close study of the personal files of William Pitt the younger, the late 18th and early 19th century prime minister who introduced income tax. Only in 1972, when an MP asked a similar question, was the full answer ready. It was long and complicated and dated back to the first division of the fiscal year in medieval times, which meant sheriffs who collected the king's income carried less money at one time, making their journeys safer. The year was later split into quarters, with the end of one accounting period fixed as the Christian feast day of Annunciation, March 25. When the calendar was reformed to take out mistakes inherent in the previous Roman system, 11 days were "wiped", putting Annunciation on April 5. Around 80 years later, in 1832, this was named as the end of the entire tax year as it was the closest quarterly date to the Government's Budget, its annual statement of income and spending. The newspaper contacted Mark Meadcroft to fill him in on the consequence of his answer 39 years ago and received a blunt response: "What a ridiculous waste of time". Source: AFP