From my days as a Russian major I was familiar with the term субботник, borrowed into English as subbotnik (what do you mean, it’s not English? It’s in the OED!) in the meaning “the practice or an act of working voluntarily on a Saturday, for the benefit of the collective”—that’s how the OED defines it, anyway; for real-world truth substitute “without pay” for “voluntarily” and replace “for the benefit of the collective” with “at the insistence of the Communist Party.” (The Wikipedia article says “The tradition is continued in modern Russia”; can this be true?) I note that the OED also includes an anglicized equivalent Saturdaying that seems to have had some currency in the years after the Bolshevik Revolution:
1920 Manch. Guardian 5 Feb. 9/7 In Moscow it has been found worth while to set up a special bureau for ‘Saturdayings’.
1920 Contemp. Rev. Oct. 504 For members of the Bolshevik party, ‘Saturdaying’ had become compulsory.
In the course of reading The Icon and the Axe, James Billington’s superb (and perennially influential) “interpretive history of Russian culture,” I have run across an earlier sense of the word:
The idea of a new church unifying Christians and Jews was gaining grass roots support in the Orel-Voronezh region with the sudden appearance of the sabbatarian (subbotniki) sect. They added to the usual rejection of Orthodox forms of worship opposition to the doctrine of the trinity, celebration of Saturday as the sabbath, and the rite of circumcision. The sect made its first appearance in the second half of Alexander‘s reign [i.e., in the years around 1820].
It turns out the sect is not only still around, Bill Aldacushion (“a descendant of Subbotniki and Molokan parents in America”) has an admirably thorough website devoted to it.
(I wonder how Morton Subotnick‘s family got their name?)