@Darryl... you seem to be implying that the quarter day/cross quarter day controversy has been resolved? When did this occur?
For those less well versed in this earth-shattering issue, the question was whether the seasons began on quarter days, or on the cross quarter days -- the former being approximately the solstice and equinox dates, the latter being the days half way between a solstice and an equinox. Or to be a little more formal: Lady Day, Midsummer Day, Michaelmas and Christmas for the quarter days, and Candlemas, May Day, Lammas and All Hallows for the cross quarter days.
Obviously, if the seasons began on the cross-quarter days, then summer begins on Mayday and runs until Lammas, and Midsummer Day is, well, in the middle, and the middle of winter is Christmas day. Otherwise, summer begins on "Midsummer's Day" and runs until Michaelmas, and winter doesn't start until Christmas, which makes the carol "In the Bleak Midwinter" a bit weird (although it scans better than "In the Bleak Early February").
Personally, I'm with that Mr. Shakespeare, who quite explicitly referred to the longest day of the year as "Midsummer", which makes the cross-quarter day camp correct and everyone else, well, heathen barbarians. Or something.