What does the old yellow calendar mean?

This is the usage of a certain sect in choosing a date, which is mainly dedicated to "God".

Daokong means that the gods are absent, and all sacrificial activities related to the gods, such as appreciating the gods, sitting at the table, opening the lights, burning incense, thanking the gods and making wishes, cannot be held. At this time, it is useless for you to perform the ceremony alone, because you can't contact the gods in the next situation.

God has gone on holiday, which means empty road.