But long before that, there is the . Simpler and more practical, it runs from December 1 to February 28 (or 29). Meteorologists invented it to keep tidy records of temperature and snowfall. For them, winter is December, January, February — three calendar months, no exceptions.

Then there is the — the one our bones know. It may begin with the first frost in November or the surprise October snow that melts by noon. It ends not on an equinox, but on that first warm April day when you forget your scarf. Felt winter has no fixed dates. It is capricious, sometimes arriving late, sometimes overstaying into muddy March.

Here’s a short, evocative text about the "dates of winter":