COLUMBIA â Missouriâs general municipal Election Day is here, and county clerks across the state are ready for voters. Polling places will open at 6 a.m. for Missourians to cast their ballots for local leaders. According to the Boone County Clerk, the office has received over 1,000 absentee ballots. These ballots included in-person and mail-in absentee voting. While in-person absentee voting closed on Monday at 5 p.m., Missourians can still drop off their mail-in ballots until Tuesday at 7 p.m. Still, the Boone County Clerk said she has seen a slightly higher number of absentee voters when compared to other April elections.