It was just past 1 a.m. today when a certain bill caught the eye of state Sen. Clarence M. Mitchell III (D-Baltimore). It would create an authority to review alternatives to Baltimore's Memorial Stadium, and Mitchell had shown little interest in it publicly.

But that changed, as things have a way of doing in the final hours of a legislative session. Mitchell's colleagues had worked on a compromise on the bill all day Saturday, wanted it passed and would loathe any delay. And Mitchell, one of the masters of the extended debate known as the filibuster, had been foiled in an earlier attempt to tie up the Senate in a bid to draw attention to one of his concerns.

The path was clear. He grabbed his microphone and leapt to his feet. "As long as I'm warmed up," Mitchell said with a grin, as exhausted senators groaned and settled back to listen, "I might as well talk on this too."

That is the kind of snag many lawmakers are dreading or awaiting, depending on point of view, when the legislature convenes Monday for the final day of the 1986 session.

With several controversial issues pending in areas as diverse as education aid, liability insurance and tax amnesty, the clock has become a player in the General Assembly's deliberations.

"It's been a productive session," said House of Delegates Minority Leader Robert R. Neall (R-Anne Arundel), who leaves the legislature this year to run for Congress. "If we have a bad day, a lot of people are going to walk away and think it's a bad session. If it's a good finish, I think people will look back on the whole session that way."

Because the remaining bills face little opposition in the House, the Senate has become the wild card of the final day. In part that is because of strong feelings on the part of some senators on a few issues, and in part that is because senators have tools of delay, such as limited restrictions on debate that allow filibusters, which are absent in the House.

"When you're down to the last 10 or 12 hours, any group of three or four senators can tie things up," said Neall. "It's funny, but it's like a hotly contested game -- I think it will all come down to the final minutes."

On the stadium bill, Mitchell's minirevolt was quickly quelled and the Senate gave the measure final approval. It now goes to the House, which is likely to go along with the House-Senate compromise worked out Saturday.

But on other issues, the two chambers are far apart. A proposal to increase state aid to local schools has become a main sticking point.

The House favors a five-year, $300 million extension to a funding formula enacted two years ago. Written by House Speaker Benjamin Cardin (D-Baltimore), who is leaving the legislature after 20 years to run for Congress, the bill is favored by Baltimore City, Prince George's and other jurisdictions that particularly need school aid -- as well as by lawmakers who wish to cap Cardin's Annapolis career on a high note.

But many senators see the measure as fiscally imprudent and unnecessary to pass this year, because the current funding formula does not expire until 1989.

"I'm not going to pass on a major educational policy decision just so this guy Cardin can see his name in marble," said one Senate critic. The conflict remained unresolved throughout the weekend as the House members charged with negotiating a compromise struggled unsuccessfully to get their Senate counterparts to sit down for an extended discussion. Their efforts to meet Saturday night were foiled when the Senate stayed to complete its work past 2 a.m. today.

The two houses face a similar conflict on a bill to create a tax amnesty program under which Maryland would join the growing list of states that are trying to raise money by giving tax delinquents a one-time, 60-day opportunity to pay back taxes without fear of prosecution. The proposal has been a popular one. But the House wants 60 percent of the money to go to local jursidictions, and the Senate wants to keep the money for state coffers.

The two chambers also are separated by a proposal to protect counties and municipalities from large damage awards by capping the amount of award they would have to pay. The Senate passed the bill and sent it over, but the House Judiciary Committee promptly amended it. When, on Thursday night, a delegate succeeded in adding an amendment that made the bill closer to the Senate version, the committee chairman had the bill sent back to committee.

Asked the fate of the beleaguered bill, committee Chairman Joseph E. Owens (D-Montgomery) said simply, "We're studying it."