Why can't you choose your parents' birthdays when you get married? Are there any bad consequences?

Don't choose your parents' birthdays. In traditional habits, parents' birthdays should not be the same as wedding auspicious days. In fact, it just means that it is not appropriate to get married on the exact date of parents' birthdays, but it is absolutely appropriate to get married within that month. We in China attach great importance to the choice of wedding date, not to say that there must be problems in choosing parents' birthdays, but that our tradition in China should also attach importance to filial piety.