What was going on when I was born?

Two groups that are often in conflict, city officials and labor leaders, met here for a weekend conference with a common concern - the migration of people and businesses from New York City - and a common goal - greater worker productivity and improved services that might halt that migration. ''It's very difficult to manage a city like New York with 2,000 managers,'' said Nathan Leventhal, Deputy Mayor for Operations, noting that the city had 180,000 government workers. Union leaders, like Victor Gotbaum and Harold Melnick, said that change among top managers in city government posed an obstacle to improving productivity and municipal services. There has been ''no continuity of management,'' said Mr. Gotbaum, president of District Council 37 of the American Federation of State, County and Municipal Employees. Mr. Melnick, president of the Sergeants Benevolent Association, added that ''the top in most of the agencies never talks to the bottom.'' Carol Bellamy, City Council President, agreed in part with the union men, saying that she thought the city did not manage its workers well. ''I consider it a miracle when two city agencies talk to each other,'' Miss Bellamy said.

Fresh from a House of Representatives victory for the Reagan Administration last week on its budget, Treasury Donald T. Regan said today that the White House was counting on popular support to ''give us the victory'' for the Kemp-Roth tax cut of 30 percent over three years. But two House Democratic leaders expressed doubt today that President Reagan could translate his popularity and momentum from his budget victory into enactment of the tax cut plan. Representative Dan Rostenkowski of Illinois, chairman of the Ways and Means Committee, said that ''unless commitments have changed,'' the Democrats and some Republicans on the panel would prefer a less extensive one-year tax cut that he has proposed, or some compromise. Mr. Rostenkowski and Thomas S. Foley, the Democratic majority whip, both called the Reagan-backed Kemp-Roth plan dangerously inflationary.

A New York State project to dredge up and safely re-bury poisonous chemical contaminants from up to 40 ''hot spots'' in the Hudson River north of Albany has been approved by the Federal Environmental Protection Agency. The cleanup of the contaminants, known as PCB's, or polychlorinated biphenyls, is to be financed with $20 million voted by Congress last year and at least $6.7 million in state funds. The project is aimed at reducing the contamination in striped bass and other fish and at safeguarding drinking water supplies and air quality. It is not, however, expected to reduce significantly the concentrations of PCB's in New York Harbor.

Charlie Lea pitched the first no-hitter in the major leagues this season as the Montreal Expos beat the San Francisco Giants today, 4-0, in the second game of a doubleheader. The Giants won the opener, 5-1. Lea, a right-hander, struck out a career high of eight batters and walked four. He became the first Expo to pitch a no-hitter since Bill Stoneman did it against the Mets on Oct. 2, 1972. Stoneman achieved the team's first no-hitter, also against the Mets, in 1969.

New York City will close the fiscal year with a $243 million surplus, its first since the early 1960's and almost twice the previously projected figure, the city's budget director said yesterday. The surplus is due primarily to an unexpected increase in city tax revenue, according to James R. Brigham Jr., the director of the Office of Management and Budget. He said the surplus would be used to insure a balanced city budget in the next fiscal year in the face of the budget cuts being sought by the Reagan Administration. Just how the surplus will be used will not be known until tomorrow when the city's budget for the coming fiscal year, starting July 1, is released. Until now, Mayor Koch's adminstration has been reluctant to be specific about the size of the surplus, fearing that demands for increased city service would ensue.

Some reminders on the green blackboard in their dressing room today told the story of the Houston Rockets' 91-86 victory over the Boston Celtics that tied the National Basketball Association championship series at 2-2. Before the game, Houston Coach Del Harris had written: 1. Block out and rebound. 2. Tough mindedness. 3. Execute offense, cut hard, look to be active. ''Tough mindedness,'' said Billy Paultz, the Rockets' 6-foot-11-inch forward, ''that was probably the key factor. It's not a pretty game anymore where teams run up and down the court and execute. It's guys banging away at each other, tempers flaring. This thing has become a war, and the Celtics know it. The team that played toughest today and the team that plays toughest for the rest of the series is going to win.''

International A Socialist will lead France for the next seven years. In a close presidential election Francois Mitterrand, the Socialist Party leader, defeated incumbent President Valery Giscard d'Estaing by what is expected to be four percentage points, a victory unexpectedly solid by French standards. For the first time since Charles de Gaulle established the Fifth Republic in 1958, control has passed from the right and center-right groupings to the left and centerleft. Exuberant Parisians sang and danced in the Place de la Bastille, the traditional celebration ground of the working class. (Page A1, Col. 6.) West Germany's coalition Government was strained by a parliamentary election in West Berlin that dealt the Social Democratic Party, the party of Chancellor Helmut Schmidt, its worst losses since World War II. No party won a majority in West Berlin, but the Christian Democrats made strong gains and became the dominant party in the city legislature, and the Social Democratic Mayor, Hans-Jochen Vogel, announced that he would step down. (A1:3.)

For close to two generations Francois Mitterrand has pursued his zigzag and unpredictable way in French politics. In effect, he has had three political careers, and the first two were unremarkable and not very successful. His triumph today, in American terms, would be remotely as if Harold E. Stassen had returned to public life 10 years ago, become a Democrat, revitalized the party and won last November's Presidential election. Served in Many Cabinets Francois Mitterrand - his name is pronounced frahn-SWAH mee-terr-AHN - was one of the blur of people moving in and out of offices in the postwar Fourth Republic, whose governments rose and fell irregularly, but often. A member of various small centrist or centerleft groupings whose names not even the French remember, he was caught up in the political moves of the time: backing the Suez invasion of 1956, affirming that the only policy to be followed toward the Algerian nationalists was war and participating dutifully in the nonstop process of political intrigues and swaps that came to be called the Waltz of the Cabinets.

In meetings at City Hall and in Albany, city and state officials concerned about competition from banks in other parts of the nation have been discussing a reduction in taxes on New York banks. Proponents of bank tax reductions say they would like to see changes enacted by New York City and the State Legislature by January. ''I think it has to happen,'' said James R. Brigham Jr., the city's Budget Director. ''It is a question of when.'' Mr. Brigham said he was convinced that the current tax rates were becoming counterproductive. He acknowledged that, with six of the nation's 10 largest banks based in New York, the state was in no danger of losing its status as the country's banking capital. But in the last few years, the industry has begun to grow more slowly in New York than in the rest of the country.

THERE comes a time when candy-coated leprechauns and Gentleman Jim Corbett's walking stick will not work, a time when gimmickry of gorilla costumes and yarmulkes must give way to the hard sell of left hooks and meaningful victories. When that time comes, ''within the next six months,'' promised Dennis Rappaport, the fighter's co-manager, ''Gerry Cooney will be the biggest attraction in sports history.'' For the time being, Cooney may leave half of Madison Square Garden's 18,000 seats empty for tonight's 10-round heavyweight bout with Ken Norton. And as one Garden boxing official said, ''We all know it is up to Cooney because Norton has never sold a quarter's worth of tickets.'' The Garden could lose more than a half-million dollars tonight - and jobs there may be jeapordized -because Cooney has not been selling tickets the way Rappaport sold his fighter to the Garden.

Despite opposition from organized labor and many Mexican Americans, the Reagan Administration is considering the institution of a large guest-worker program as a means of improving United States-Mexican relations and curbing illegal migration. Campaigning in Texas last September, Mr. Reagan called for a policy that would permit hundreds of thousands of Mexicans to enter this country and work on a temporary basis. In a television interview March 3, the President said he was ''very intrigued'' with a proposal to legalize the illegal migration from Mexico by granting visas to those who wanted to go back and forth across the border while holding jobs in this country. Mr. Reagan said he wanted to discuss the idea with Mexico's President, Jose Lopez Portillo, who is scheduled to visit Washington June 8 and 9. The White House staff has developed a detailed proposal for a guest-worker program. Although the President has not yet reviewed it or received advice from his Cabinet, he is widely believed to favor such a program. ''On this question,'' one official said Friday, ''there is a strong tidal force that stems straight out of the Oval Office.''

The Social Democratic Party of West Berlin suffered its worst losses since World War II in city elections tonight, straining the West German coalition Government of Chancellor Helmut Schmidt. No party won a majority in the voting for the city Parliament, but the Christian Democrats made strong gains and became the dominant party in the legislature. After early projections of the election results, West Berlin's Social Democratic Mayor, Hans-Jochen Vogel, announced that he would step down. The Christian Democrats indicated that they would try to form a coalition government with the West Berlin Free Democrats, enticing them away from their traditional association with the Social Democrats, who are also their coalition partners in the federal Government in Bonn.