According to Section 195-35 of the town's charter. Political signs are not to be put up until 21 days before an election and must be removed within 14 days after.

Political signs. Temporary, freestanding political signs, not exceeding in aggregate 24 square feet in area, which are designed to influence the action of voters for the passage or defeat of a referendum question or other measure appearing on the ballot of an election duly called in the Town of Chelmsford or designed to influence the action of voters for election of a candidate whose name appears on the ballot of an election duly called in the Town of Chelmsford are allowed in all districts. Such signs may be erected no sooner than 21 days prior to the date of election and must be removed not later than 14 days after such election. Signs permitted by this subsection shall not be higher than three feet above ground level; shall not be artificially illuminated; shall be freestanding and not attached to a building, tree, utility pole or fence; shall be set back at least 15 feet from the street line; and shall only be located within the front or side yard area of the property. These signs require no sign permit.