Today, January 7, is both Plough Monday and Distaff Day. The two don’t always coincide.
Plough Monday, as the name indicates, is a Monday: specifically, the first Monday after Epiphany, January 6. Distaff Day is the very day after January 6.
The two days mark the return to normal work after the Christmas holidays. On Plough Monday the agricultural season began, and the men returned to the plough. On Distaff Day regular housekeeping resumed, including working at the distaff (later replaced by the spinning wheel).
The old rhyme goes,
Yule has come and Yule has gone,
And we have feasted well;
Now Jack must to his plough again
And Jenny to her wheel.
This year, the day after Epiphany is also the first Monday after Epiphany, so the two days coincide.
So there you are.
(This information is drawn mostly from many past issues of The Old Farmer’s Almanac, which I’ve read faithfully since 1976. Though it’s a reliable publication, fact checking is always a good idea, and was done.)