Chapter 28
A Miscellany Including Stationery, Clocks, Noises, Baby Carriages, Remuneration and Advance Preparations
CLOCKS AND WATCHES
19.a. Winding up a watch or a clock is, subject to the exceptions mentioned below, forbidden, since this amounts to putting the finishing touches to an instrument which would otherwise be unusable for its intended purpose.
19.b. One should not wind up a watch or a clock even while it is still going.
20.a. Nevertheless, one may wind up a watch or a clock where the following conditions are all satisfied:
1) one needs it in order to attend to the requirements of a person who is ill, for instance, to know when to feed him at regular intervals;
2) there is no non-Jew available who could wind it;
3) it is still going at the time of winding.
20.b. In addition, there are authorities who permit a watch or a clock to be wound up where the following conditions are all satisfied:
1) one needs it in order to perform a mitzva, for instance to know when it is time to go to the synagogue or to study Torah;
2) there is no non-Jew available who could wind it;
3) it is still going at the time of winding.
20.c. On yom tov sheini shel galuyoth, it is permitted to wind up a watch or a clock
1) which is still going,
2) so long as one is winding it for use on that same day.
