1, that's because there are no high mountains in some areas, so some people think of "eating cakes" because of "climbing", which means eating cakes instead of climbing, and because they only eat cakes on the Double Ninth Festival, they are called "Chongyang cakes".

2. In ancient times, the married daughter was taken home on September 9th, so this day was also called "Daughter's Day". Because September 9th, "Nine" and "Old" are homophonic, our government has designated today as "Old People's Day".