168. Private Holidays

Avodas Kochavim 9:4

The members of the Canaanite nations are idolators and Sunday is their holiday. Therefore, it is prohibited in Israel to conduct business with them on the Thursday and Friday of each week. It goes without saying that one may not do so on Sunday itself; transactions with them are prohibited everywhere on that day.

Avodas Kochavim 9:5

The day on which idolators assemble to crown a king, offer sacrifices, and praise their idols is considered one of their holidays. On a day that only a single idolator observes as a holiday, on which he thanks and praises his idol – such as his birthday, or the day on which he shaves, returns from a voyage at sea, is released from prison, marries off his son, etc. - it is only prohibited to conduct business with that individual on that day. Similarly, if the practice is for idolators to commemorate one of their number’s passing with festivities, one may not conduct business with the celebrants on that day. If someone’s passing is marked by the burning his possessions and offering incense, we may assume that idolatry is involved. This only applies to those who worship the idol. One may conduct business with those who participate in the festivities by eating and drinking, because it’s the custom, or in order to honor the king.