Midwinter. That's MID-Winter

Okay. I understand (I guess) how lots of people have gotten the notion that the Solstice is "the first day of winter". But how on Earth can somebody write this paragraph (from The Writer's Almanac, by the way - emphasis mine):

In the northern hemisphere, today is the Winter Solstice, the shortest day of the year and the longest night. It's officially the first day of winter and one of the oldest known holidays in human history. Anthropologists believe that solstice celebrations go back at least 30,000 years, before humans even began farming on a large scale. Many of the most ancient stone structures made by human beings were designed to pinpoint the precise date of the solstice. The stone circles of Stonehenge were arranged to receive the first rays of midwinter sun.

I mean, come on, guys. In the same paragraph you call it the first day of winter and midwinter?

Look it up:

Main Entry: mid·win·ter
Pronunciation: mid|wint(r)
Function: noun
Etymology: Middle English, from Old English, from midd, midde mid + winter -- more at MID, WINTER
: the middle of winter

Main Entry: midwinter day
Function: noun
Usage: usually capitalized M&D
archaic : CHRISTMAS

Citation

"midwinter" and "midwinter day." Webster's Third New International Dictionary, Unabridged. Merriam-Webster, 2002. http://unabridged.merriam-webster.com (21 Dec. 2006).

As Jane Harrison put it in Ancient Art and Ritual, referring to the ancient Greeks:

The year with its 365 days is a Sun-Year. Once this Sun-Year established and we find that the times of the solstices, midwinter and midsummer became as, or even more, important than the spring itself. The date of the Daphnephoria is not known.

In many countries (for instance, Sweden or Estonia) the big holidays are Christmas (midwinter) and Midsummer Day. Note the names...

If today is the beginning of winter, then winter is entirely composed of shortening days. That doesn't even make sense.

The Solstices are Midwinter and Midsummer. The equinoxes are mid-spring and mid-autumn (though we don't use those names). They're not the first day of anything.