What was going on when I was born?

A Federal judge ruled yesterday that the physical test for applicants to New York City's Fire Department discriminates against women. He said that a new test must be developed and that up to 45 women must be appointed to the department. In his ruling, Judge Charles P. Sifton said that the test did not ascertain the qualities needed to perform well as a firefighter. The test involved such things as carrying a 120-pound dummy on one shoulder up and down a flight of stairs, scaling an eight-foot-high wall and running one mile.

Secretary of State Alexander M. Haig Jr. met today with the second-ranking member of the Salvadoran junta as the State Department continued to insist that Nicaragua and Cuba were directing the guerrilla operation in El Salvador. But department officials were clearly concerned about the attention given Mr. Haig's dramatic announcement on Thursday to a House subcommittee that evidence of outside interference in El Salvador could be seen in the capture of ''a Nicaraguan military man'' helping to direct the insurgency. Their concern was that the attention given the one Nicaraguan would detract from what the Administration regards as very compelling evidence, a view shared by both intelligence committees in Congress, that Nicaraguans and Cubans are deeply involved in the Salvadoran insurgency. Reports from Mexico, confirmed late in the day by the State Department, said a Nicaraguan was inside the Mexican Embassy in San Salvador, having either eluded the Salvadoran police or having escaped from them.

Tubby Clinton left his steel-toed boots in the kitchen, padded over to the front room and handed his wife the little slip of paper. ''Here it is,'' he said. ''Here's the big one.'' Mrs. Clinton read the paper. It said ''Notice of Layoff'' and informed Donald C. Clinton, time-card No. 80421, that he would be laid off at the end of his shift today, March 5, 1982. Signed L.W. Alley for Whitehead & Kales Company.

The chairman of the House Budget Committee said today that the Democrats needed a signal that President Reagan would compromise on the already enacted tax cuts before they could really work on a bipartisan budget alternative. Without such a concession, the chairman, Representative James R. Jones, said, ''I'm very concerned about a stalemate, because it could send the wrong signal to the financial community that we cannot get hold of our fiscal policy, and that could unravel economic recovery very quickly.'' The Oklahoma Democrat said any budget alternative should include some tax increases and cuts in the growth of military spending, both of which the President has strongly opposed. He also said reductions in the automatic inflation increases in aid programs, including Social Security, were needed and some restoration of funds for education and job training. Mr. Jones, for the first time, said that his budget analysts had produced proposals to cut $42 billion over three years from the military spending increases proposed by the President.

As layoffs continued in the nation's heavy industries, the rate of unemployment in February climbed threetenths of a percentage point to 8.8 percent. In January the rate dropped to 8.5 percent of the labor force, which analysts attributed to a statistical quirk and severe winter weather. The rise last month returned the rate to the 8.8 percent it reached in December, the second highest since the beginning of World War II. The highest jobless rate since the start of the war was 9 percent, reached in May 1975.

Negotiators for New York City have offered to cut Madison Square Garden's real estate taxes by about 75 percent, almost $3 million a year, as part of a package to keep the Rangers and Knicks from leaving for the suburbs, a source involved in the negotiations said yesterday. He said the concession by the city would account for most of a $5 million-a-year saving the Garden was seeking in return for a commitment to keep the hockey and basketball teams, which it owns, in New York. Garden officials contend that the arena lost about $8 million last year and has never shown a profit since it was opened in 1968. Cooperation Necessary The source, who asked not to be identified because of the delicacy of the negotiations, said the total savings could be achieved in a three-point plan that the city and the Garden appear agreed on but that requires cooperation at the state level and from labor unions whose members staff the arena. The three points are: - The real estate taxes, currently about $3.9 million a year, would be cut about $3 million, to a total of about $900,000 a year.

Reporting that tax evasion appears to be increasing, Senator Bob Dole, chairman of the Finance Committee, announced today that he was sponsoring new enforcement measures, including a requirement that brokerage firms report customers' profits in the stock market to the Internal Revenue Service. In releasing new I.R.S. estimates, Senator Dole and a second Finance Committee Republican, Charles E. Grassley of Iowa, said that $76 billion in Federal income taxes probably went unpaid in 1981, three times higher than the 1973 figure of $21 billion. Higher Percentage of Unpaid Tax ''That growth reflects increasing percentages of unpaid tax,'' most of it on lawful income and profits that persons did not report, Senator Dole said. Among the new figures was an estimate that 44 percent of all capital gains - profits on the sale of securities, real estate, commodities and other forms of wealth - went unreported. The previous estimate was 20 percent.

A New York Court of Appeals judge yesterday extended until March 22 the order that prevents the demolition of the Morosco and Helen Hayes Theaters to make way for the new Portman Hotel on Broadway. At that time the full court will decide whether to take up the case. The judge, Jacob D. Fuchsberg, acknowledged that his decision could have an ''unsettling effect'' on the proposed hotel, which would rise on the site of the two theaters. However, he also said, ''I can but confidently expect that, in perspective, this short additional stay will not be a straw that will break the camel's back.''

In a side room at a hotel here, just before plunging into a crowd of French residents who had eaten a 60-foot buffet lunch while waiting for him, President Francois Mitterrand reflected on the two-day visit he was about to end. ''The only new thing,'' he said, ''was that I said the same thing.'' In Israel, where his visit broke a 15-year-old tradition of official French aloofness, Mr. Mitterrand coupled warm words for the Israelis with an assertion that the Palestinians were a people with the right to a state. Earlier, in visits to Egypt, Algeria and Saudi Arabia, he coupled warm words for the Palestinians with the assertion that Israel was a legitimate state with a right to security.

Prime Minister Menachem Begin, who fell ill Thursday at a dinner given by President Francois Mitterrand of France, was reported to be feeling better today. A spokesman said the 68-year-old Prime Minister would be back at work Sunday after suffering from fatigue over the pressure of recent events.

China will soon release its remaining Nationalist military and civilian prisoners, many of whom have been imprisoned since the Communists came to power more than 32 years ago, the country's senior security official said today. Zhao Cangbi, Minister of Public Security, said the pardon would apply to all 4,237 former Kuomintang government and military personnel, as well as ''special agents'' still in custody. Mr. Zhao announced the proposal, which is virtually certain to be approved, at a session of the Standing Committee of the National People's Congress, China's nominal parliament.

Carlos, the Venezuelan-born international terrorist, has threatened to attack France's Interior Minister and other Cabinet members unless they release two recently arrested terrorist suspects within a month, officials disclosed today. Interior Ministry officials said the threat was contained in a letter bearing two thumbprints that the French police identified as those of the terrorist linked to a series of guerrilla attacks in the 1970's. It is the first firm evidence in nearly seven years, the officials said, that Carlos, whose real name is believed to be Ilyich Ramirez Sanchez, is still alive and active. Defferre Is Singled Out The letter, written in Spanish and delivered to the French Embassy in The Hague early Monday morning, was said by the Interior Ministry to demand the release of Bruno Breguet, 32 years old, a Swiss student, and his West German companion, Magdalena Kaup, 34. They were arrested in Paris on Feb. 16 as they fled from an underground parking lot on the Champs-Elysees.