'Rock Day' definitions:

Definition of 'Rock Day'

From: GCIDE

Distaff \Dis"taff\, n.; pl. Distaffs, rarely Distaves. [OE. distaf, dysestafe, AS. distaef; cf. LG. diesse the bunch of flax on a distaff, and E. dizen. See Staff.]
1. The staff for holding a bunch of flax, tow, or wool, from which the thread is drawn in spinning by hand. [1913 Webster]
I will the distaff hold; come thou and spin. --Fairfax. [1913 Webster]
2. Used as a symbol of the holder of a distaff; hence, a woman; women, collectively. [1913 Webster]
His crown usurped, a distaff on the throne. --Dryden. [1913 Webster]
Some say the crozier, some say the distaff was too busy. --Howell. [1913 Webster]
Note: The plural is regular, but Distaves occurs in Beaumont & Fletcher. [1913 Webster]
Descent by distaff, descent on the mother's side.
Distaff Day, or Distaff's Day, the morrow of the Epiphany, that is, January 7, because working at the distaff was then resumed, after the Christmas festival; -- called also Rock Day, a distaff being called a rock. --Shipley. [1913 Webster]