Colorado ballots are going out to voters for the election. Here are the key voting deadlines to know.

Voting season begins Friday in Colorado as ballots start hitting the mail, headed to the state’s 3.9 million active registered voters.

A bipartisan group of county clerks gathered next to a ballot drop box in Highlands Ranch on Thursday morning to mark the occasion. They shared key election dates and deadlines and — amid still-prevalent election denialism and baseless conspiracy theories — emphasized that Colorado’s paper ballot-based election systems are accurate and secure.

“Every voter should have confidence that we are running uniform processes in each Colorado county that produce accurate results — and that the security of each ballot and the tabulation process is our highest priority,” said Douglas County Clerk and Recorder Sheri Davis, a Republican.

Davis urged voters to contact their local clerks if they have any questions about the security of the voting process. She also put out a call for more people to serve as election judges on the bipartisan teams of workers who gather and process ballots every November.

“These are people from your own community, representing different political affiliations, who help complete every step of the process to make sure your vote counts just like it’s supposed to,” she said.

Here are some key dates for voters to be aware of ahead of the Nov. 5 election:

• Friday: Clerks’ offices begin mailing out ballots to active registered voters, with batches going out over the next week. Friday also is when secure ballot drop boxes open across the state. Those boxes will be under continuous video surveillance to ensure their integrity and to protect voters from potential intimidation.
• Oct. 21: Voter service and polling centers — staffed by the bipartisan teams of election judges — will open in counties across the state. They will offer in-person voting, voter registration and replacement ballots for people whose mailed ballots may have been lost or damaged. The centers will be open through 7 p.m. on Nov. 5, when voting ends. Voters should check their county clerk’s website for locations.
• Oct. 28: This is the last day for voters to put their voted ballots in the mail if they plan to return them that way. Any later, voters risk having their ballots arrive after the legal cutoff time at 7 p.m. on Election Day; postmark dates do not count.
• Nov. 5: On Election Day, voters can vote in person at polling centers until 7 p.m. or deposit their ballots in drop boxes until that time.
• Nov. 13: The deadline for voters to cure problems with their ballots if they have been contacted by their local clerk’s office about discrepancies.

That last deadline comes as election workers process the paperwork after voting ends. They will set aside ballots with discrepancies, such as missing voter signatures on the envelope or signatures that do not match state records. Clerk’s offices will then notify voters to allow them to address those discrepancies, or “cure” those ballots, and have them counted.

Other rules and hints

While the voting period is underway, Molly Fitzpatrick, Boulder County’s Democratic clerk and recorder, said it is illegal for people to approach or intimidate voters at drop boxes or voting centers. Nonvoters must stay 100 feet from drop boxes or face potential legal consequences, Fitzpatrick said.