Fasting after Pesach – Ask the Rabbi
Q. Why do some people fast on three days (Monday, Thursday and Monday) at the beginning of the month after Pesach?
A. These are some of the explanations:
Similar fasts after Sukkot have the same reasons. In both cases the fasts do not take place immediately after the festival but at the beginning of the ensuing month. Until then we are still experiencing the yom-tov spirit.