State legislatures face a lot of unfinished business

''Do the day's work'' and ''be brief.'' This advice from Calvin Coolidge to the Massachusetts Senate in 1913 appears long forgotten. Legislative sessions, which in ''Silent Cal's'' day rarely lasted six months, now run considerably longer.

With summer waning, legislatures are still in session or are set to return to work after recesses in California, Colorado, Illinois, Massachusetts, Michigan, New Jersey, New York, Ohio, Pennsylvania, and Wisconsin.

In California, the Democratic-controlled Senate and Assembly and Republican Gov. George Deukmejian are at odds over local-aid funding. The governor wants to appropriate some $600 million, part of the $1.3 billion he deleted from the $27. 3 billion 1984 state budget approved by lawmakers in July. Democratic leaders have proposed a local-option increase in the sales tax to provide the funds.

Also on the docket is more money for community colleges. Governor Deukmejian favors replacing the current free-tuition setup with a $50-a-semester fee. But legislators would appropriate funds.

In Colorado, the Legislature must deal with a projected 1984 deficit of up to Legislature have proposals, involving budget cuts and tax boosts, for resolving the situation. Also to be considered are measures to protect water resources and change property-tax exemptions.

When Illinois legislators return to work on Oct. 5, the top item on the agenda of the Democratic-controlled Legislature will be efforts to override various vetoes by Republican Gov. James Thompson. It also will try to come to grips with prison overcrowding, possibly by allowing two inmates to a cell in some of the newer institutions or by providing for some sort of early-release program.

Massachusetts lawmakers, who returned Monday, have pending a $1.2 billion bond authorization for road and bridge construction, $196.6 million for new housing, and $258.8 million for other construction projects. Also on the agenda are proposals to let communities regulate condominium conversion, to reform workmen's compensation, and so-called right-to-know legislation requiring employers to advise workers of dangerous substances and conditions on the job.

Efforts to raise the drinking age from 20 to 21 also will be pushed.

Lawmakers in Wisconsin, one of only four states where liquor of all types is legally available to 18-year-olds, are considering such action, too. Gov. Anthony S. Earl backs a minimum age of 19, but some legislators are pushing for 21, or at least to 20.

Other key items on the docket when the Wisconsin legislative session resumes Oct. 4 are long-term loans to small businesses, state bonds to guarantee fixed-rate financing for manufacturers, and increased exemptions from capital gains taxes for companies investing in plants and machinery.

Legislative debate in Michigan, where lawmakers returned Tuesday, is also expected to center on means for boosting the state's economy. Creation of a new ''strategic investment fund'' that will pool state money and private resources to help produce jobs will likely command prime attention.

How to spend $3 million in social service funds, appropriated in the fiscal 1984 state budget, appears to be a particularly hot issue.

The Michigan sitting may also zero in on changes in legislative and congressional districts, presumably to bring them into closer conformity to ''one-man, one-vote'' standards. Lawmakers in New Jersey and New York will be tackling that question, too.

The New Jersey Legislature, which resumed Sept. 6, must take up redistricting , since the US Supreme Court in June struck down the current state plan, rushed through the Democratic Legislature early last year and signed into law by lame-duck Democratic Gov. Brendan T. Byrne. The realignment, which must be completed before the 1984 elections, could prove difficult, since although Democrats still control the Legislature, the governor is now Thomas Kean, a Republican.

Car insurance reform is another hot issue in New Jersey, which has the highest rates in the US. An investment program to finance replacement of roads, bridges, and various state facilities is also at issue, as are proposals for shoreline protection and provision of energy assistance for the elderly.

In New York, besides taking a close look at districting (in light of the Supreme Court decision involving New Jersey), lawmakers, upon their return Thursday, must come to grips with possible changes in the $1.25 billion transportation improvement program.

Pennsylvania legislators will decide the fate of eight state licensing boards when they come back to work Sept. 19.

Ohio legislators, who return Sept. 27, may tackle the adjustments in utility rates, banning the free distribution of cigarettes, increases in court fees, and mandatory loss of driving license and registration for those convicted of a first drunk-driving offense.