What sort of a question is that, you might ask?

Well the fact of the matter is that the somewhat unknown fast of the 10th Tevet is the only Jewish fast that in certain years can fall on a Friday, the eve of Shabbat. Was this intentional ? Was this a plan of the rabbis to focus on a somewhat neglected holy day?

Indeed, it was not! The fact is that the fast of the 10th Tevet falls on a Friday only because of the quirks of the Jewish calendar. This occurrence is not a goal but an outcome of the mathematical nature of the lunar calendar and the constraints placed on the positioning of other special days within it.

For example, Yom Kippur can never fall on a Friday or a Sunday; Hoshanah Rabbah (during the festival of Sukkot) must never perchance on a Shabbat. This fast happens to fall on a Friday some 20% of the time, as it did three years ago and as it will again in four years time.

Friday's Foregone

Friday seems to have fared badly as far as fasts are concerned: If the fasts of Tammuz, 9th Av, or Gedalia fall on the Shabbat, they are postponed to Sunday. The Fast of Esther, for its part, is brought forward - to Thursday - since the following day would have been Purim and fasting on Friday is generally not considered a timely way to bring in the Sabbath.

So why not "bring forward" the Fast of the 10th Tevet and do away with this awkward manner of welcoming the Shabbat? Well, those fasts mentioned above were going to be moved anyway (only on Yom Kippur do Jews fast on Shabbat). However, there is no precedent or halachic grounds for moving our fast to any other day.

So, Friday stays! And for those who are interested that also means the occurrence of the only Friday afternoon reading of the Torah (and additional Haftarah) in the entire Jewish year! Those who are fasting are asked to take care: Continue until after sundown well into the Sabbath before you "break" that fast!