Today, being 24th June, is Midsummer Day, one of the four quarter days in England - and probably Wales as well although not in Scotland. Quarter days are the days when rent is traditionally due to be paid - and still, in the case of many commercial rents - and servants were traditionally hired.
All four quarter days fall on religious festivals: Lady Day (25th March) is also the Feast of the Annunciation; Midsummer Day (24th June) is the feast day of St John the Baptist; Michaelmas (29th September) is the feast of St Michael and All Angels; while the fourth quarter day is 25th December, There is an easy way to remember which day of the month is the quarter day. March has five letters, so that quarter day is on the 25th. June, with four letters, has its quarter day on the 24th. September has nine letters, so the 29th is the quarter day, and December has eight letters . . .
Up to 1752, Lady Day was the first day of the year in England - goodness knows why such an odd day was chosen! But in that year, the calendar in England was changed from the Julian to the Gregorian, with Wednesday 2 September 1752 being followed by Thursday 14 September 1752 (an early example of England falling into line with the continent). The old calendar had been getting out of kilter with the solar system or something, and 11 days had to be lost. There were demonstrations in the streets with people complaining that the state had stolen 11 days of their lives! The act of Parliament (the Calendar (New Style) Act 1750) also changed the day on which the new year started from 25th March to 1st January. However, so that investors would not lose 11 days interest, the start of the financial year would be 6th April, which is the Gregorian equivalent of 25th March under the Julian calendar.
Which is why our tax year still starts on 6th April.