Maine’s Constitution says that laws enacted by the Legislature must take effect 90 days after the session’s end. This year, that date falls on Thursday, Sept. 20.

The Constitution also leaves room for exceptions for “emergency” laws, which take effect immediately upon the governor’s signature. One notable example this year is a bill to prevent protesters from taunting or insulting people who turn out near soldiers’ funerals. Gov. John Baldacci signed it into law May 18.

Other bills include specific trigger dates in their language or are phased in over multiple effective dates. One new law stipulates that new fees on oil changes will take effect Oct. 1, and another says only warnings can be issued under Maine’s bolstered safety belt law until April 2008, when tickets can be issued.

Another new law, which kicks in Jan. 1, 2008, requires retailers to accept at no charge used cellular telephones for recycling and bars their disposal in landfills.