Alameda County officials want to remind voters that Election Day is Nov. 4 after the county's registrar of voters sent return envelopes that say, Election Day is November 5, 2014" to 27,000 Berkeley voters.
All other materials sent to those voters have the correct date, county election officials said.
"This is an unfortunate error on some vote-by-mail envelopes sent to voters in Berkeley, and we deeply regret any confusion this may be causing," Alameda County Registrar of Voters Tim Dupuis said in a statement.
Dupuis's office is mailing letters to each voter that received the erroneous return envelopes and is sending emails to each voter that provided an email address to the registrar. The office will also be telling voters of the correct date through social media sites such as Twitter and Facebook.
"We are glad that we discovered the error relatively early in the process," Dupuis said. "This will allow us to take a number of corrective measures in the coming weeks to remind our voters that Election Day is Tuesday, Nov. 4."
A printer used by the county and other large counties in California has taken responsibility for the error. Dupuis said his office is taking additional safeguards to avoid misprints in the future.
More than half of registered voters in Alameda County vote by mail. The 27,000 voters who received the misprinted envelopes represent about 6 percent of the 422,000 voters who are registered to vote by mail in Alameda County.
This election year, voters in the county are deciding between 278 candidates and 30 different ballot measures. This means the printing task was challenging because voting guides are as thick as 130 pages and there are 158 different ballot types, according to the registrar's office.
The Alameda County Registrar of Voters must receive a voter's mail-in ballot no later than 8 p.m. on Election Day, according to California law.
Voters in Berkeley, Oakland and San Leandro will have to pay 91 cents in postage to mail their ballot, which contains three cards. Voters in other communities in the county must pay 70 cents to mail two ballot cards.