the world > action or operation > inaction > [noun] > day on which an activity does not take place
by-day1637
1637 W. LaudSpeech in Starr-chamber 18 Upon those by-dayes [i.e. days when there is no sermon] to runne to other Churches.
1857 G. A. LawrenceGuy Livingstone v. 41 Being park-hack in the summer, and cover-hack in the winter, with a bye-day now and then when the country's light.