There is a question asked about Tisha BeAv when it falls out on Motzae Shabbat. When should a person remove his leather shoes? We wear leather shoes for Shabbat, but we may not wear leather shoes on Tisha BeAv. So at what precise time should we remove our shoes when Tisha BeAv falls out on Motzae Shabbat?
According to Chacham Ben Tzion, leather shoes must be taken off by sunset. But wouldn’t that be a problem since technically the time of sunset is still Shabbat? Shabbat doesn’t end until much later, and we are not permitted to do anything explicitly evident that is for mourning on Shabbat. Therefore, Chacham Ben Tzion says that at sunset one should remove his leather shoes in an inconspicuous manner. Meaning, one should remove his shoes in such a way that it is not obvious that it is being done for Tisha BeAv. One should remove his shoes as if he were taking a nap or lying down.
So again, when Tisha BeAv falls out on Motzae Shabbat, one should remove his shoes by sunset in such a fashion that it is not clear that it is for Tisha BeAv.