Only after receiving the marriage certificate is a legal couple at the legal level, the husband and wife are protected by the marriage law, is the real "marriage", so the wedding anniversary should be the day of the marriage certificate, rather than the day of the banquet.
A wedding anniversary commemorates the day when two people actually become "husband and wife." Whether two people are husband and wife relationship, the most fundamental basis is the marriage certificate!
Marriage certificates are legally valid. A marriage certificate is a couple that the state knows, recognizes and is protected by law. If there is no marriage certificate, just held a banquet, it is only a "formal" husband and wife, and does not belong to the real sense of the marital relationship recognized at the national legal level.