I say "official" in quotes because technically it was yesterday, ("E-29" in election administration parlance) October 8, but that was Columbus Day and officially a federal and state holiday. No mail is delivered, so nothing can get sent out.
Some counties were open, some were closed, some were processing "counter ballots" where people can walk in and vote in person.
Last month when we were putting together the new California Online Voter Guide I was trying to figure out what date to put for "First Day to Request a Vote-by-Mail ballot". Was it the 8th or the 9th? I emailed my local registrar who informed me I was correct, it should technically be the 8th but is actually the 9th.
Why does this matter? It seems a lot of people are worrying about where their ballots and election materials are. The California Voter Foundation has received an unusually high number of queries from voters wondering why they have not received anything yet.
Fortunately there are tools online voters can use to verify registration or check the status of a vote-by-mail ballot. CVF's Directory of County Election Offices provides links to the county web sites where voters can not only look up their vote-by-mail ballot status, but also registration status, personalized ballot pamphlet, and polling place location. Some counties let voters request vote-by-mail ballots online too.
Whether counties provide any or all of these tools varies widely from county-to-county. As in so many areas of elections, these variations make it hard for people like me to explain clearly to California voters how to interact with our state's voting process.
But one thing is certain: starting today voters should watch their mailboxes for arriving county sample ballots and vote-by-mail ballots. If these election materials don't show up it's a good indication you are not registered at your current address. You can register online or on paper (forms are at most post offices) up until October 22.