I have library books that are overdue and will acrue fines. I wanted to finish reading them but will not be able to finish before the end of the weekend. Must they be returned beforehand to avoid fines accruing on Shabbat? (In other words, if fines accrue on Shabbat, is that transgressing by spending money?)
Thank yo for your question.
Paying the fine to the library for the extra time the book was kept is not a problem regarding Hilchos Shabbos. The potential issue, called “schar Shabbos” is to earn money from a rental or work, however it is only if all the work was done only on Shabbos. With the penalty for the library book, each day is calculated from midnight to midnight, therefore each calendar date comprises a part that isn’t Shabbos, and therefore it isn’t an issue. Additionally, the prohibition of receiving payment is on the receiver. The one who is paying is violating lifnei placing a stumbling block in front of others. In this situation where the receiver of the money is a gentile, it isn’t an issue since they are not bound by these halachos.
ע’ רש”י כתובות ס”ד. ד”ה שכר שבת גזירה משום מקח וממכר, א”ר ס’ ש”ו- י”ד שגזירת מו”מ ושכר שבת כולה חדא גזירה היא. מ”ב ס’ ש”ו , ,ס”ק ט”ו מפרמ”ג. והאיסור ביו”ט ס’ תקפ”ה סע’ ה’, מ”ב שם ס”ק כ”א.