|It's conceivable the registrar-recorder/county clerk MIGHT have the authority to reject a deed that contains a date that is obviously incorrect on its face (for example February 31, 2020) or that cannot be understood by a person reasonably competent in the English language. But the US Constitution recognizes the people's right to freedom of expression. The default position is people can write any way they please, and to limit it, the government must pass a law or regulation, and possibly, defend that law or regulation in the courts.|
I call on you to cite the law or binding regulation that places any limitation on how dates may be written in California recorded documents, or on California notarial certificates.
For my part, since California explicitly accepts notarial certificates completed out of state, if done in conformance with the laws of the place where the notarial act is performed, I would expect a registrar-recorder/county clerk to accept my Vermont notarial certificates no matter how I wrote the date, as long as it is understandable to a person who speaks English. All these should be acceptable: June 7, 2020; 7 June 2020, the seventh day of June in the year of the Lord 2020; the 159th day of 2020. The ever-popular 6/7/2020 is more subject to criticism than the rest, since in some English-speaking countries, it means July 6, 2020.