A special state primary will be held April 30 to fill the vacancy caused by the resignation of U.S. Sen. John F. Kerry to become secretary of state. For Cambridge residents not already registered, the last time to register to vote is 8 p.m. April 10.

The polls will be open from 7 a.m. to 8 p.m Election Day.

Any voter who is unable to go to the polls Election Day because of physical disability, religious belief or being away from the city may request an absentee ballot from the Cambridge Election Commission by noon April 29. Absentee ballots may be mailed to voters (if requested with enough time), or such voters may choose to vote at the commission office during regular city office hours: Mondays from 8:30 a.m. to 8:00 p.m.; Tuesdays through Thursdays from 8:30 a.m. to 5 p.m.; or Fridays from 8:30 a.m. to noon. The office will also be open for absentee voting from 8:30 a.m. to 5 p.m. April 26.

For information, visit the commission office at 51 Inman Street, call (617) 349-4361 or visit our website.