not to be THAT NERD but in the UK at least, the financial year (April 6th - April 5th) was aligned with the start of the new year which was March 25th.
The old financial year started on 25th March, which was also new year's day (and also the point that the year incremented, so if you were knocking around on March 24th 1300 the next day would be March 25th 1301.
But when everyone changed to the Gregorian Calendar - which added 11 days to the calendar to make up for some sloppy Papal mathematicians who didn't believe in things like astronomy or leap years - the tax year had to be shifted to be April 6th, because while everyone else was happy to work around things, the tax office was NOT going to have a tax year that was 11 days shorter because that would have meant less money.
So basically, when the calendar changed happened, new year was set as 1st January (yawn, stupid time to have new year!) at which point the year count incremented up by one year, and the tax year stayed (and still stays) as April 6th, which was really March 25th but with some days tacked on.
The old financial year started on 25th March, which was also new year's day (and also the point that the year incremented, so if you were knocking around on March 24th 1300 the next day would be March 25th 1301.
But when everyone changed to the Gregorian Calendar - which added 11 days to the calendar to make up for some sloppy Papal mathematicians who didn't believe in things like astronomy or leap years - the tax year had to be shifted to be April 6th, because while everyone else was happy to work around things, the tax office was NOT going to have a tax year that was 11 days shorter because that would have meant less money.
So basically, when the calendar changed happened, new year was set as 1st January (yawn, stupid time to have new year!) at which point the year count incremented up by one year, and the tax year stayed (and still stays) as April 6th, which was really March 25th but with some days tacked on.
1752 must have been a pretty confusing year.