What was going on when I was born?

President Reagan's top aides told him the Federal Reserve should be headed by either Paul A. Volcker, whose term as chairman expires Aug.5, or the economist Alan Greenspan, according to Administration officials. They said Mr. Reagan had made no decision yet, and might name someone else. (Page A1.) Treasury Secretary Donald T. Regan criticized Democratic attempts to cap the third year of the personal tax cut. (D10.) The Supreme Court, in a setback for the I.R.S., ruled that the agency, like any other creditor, can be required to return property it has seized from a company that later files for bankruptcy. The Court also ruled that antitrust law permits individuals to serve simultaneously as directors of banks and rival insurers. And it ruled that Alabama may not bar natural gas producers from passing along to interstate consumers an increase in the state's severance tax. (D9.)

A Federal judge yesterday ordered a new vote in the bitter GAF Corporation proxy contest, thus upsetting the victory claimed only a month ago by Samuel J. Heyman, a dissident GAF shareholder. That unofficial outcome, which resulted in Mr. Heyman's slate of 10 directors unseating GAF's current management, was challenged by the company on the ground that Mr. Heyman withheld damaging information from his proxy material that might have cast doubt on his fitness to serve as a director. Mr. Heyman said he was ''shocked and surprised'' by the decision and would appeal it. In beginning the proxy fight earlier this year, he had charged that Jesse Werner, GAF's 66-year-old chairman, had mismanaged the company, selling off assets to stay in business despite poor profitability. He had called for the sale of GAF's two remaining major divisions, its chemical and roofing businesses.

President Francois Mitterrand, reacting to accusations that France has slipped into a crisis of authority, reasserted in a national television interview tonight that he is in firm control of the nation. ''I assume my responsibilities and I consider myself the first person responsible for public order,'' Mr. Mitterrand said in response to demonstrations that culminated last week in a protest march to the Justice Ministry by several thousand policemen. The statement, made in the fourth television appearance by Mr. Mitterrand since he took office two years ago, was aimed at combating a widening notion in the press and in public opinion here that France is sliding toward disorder and economic debility.

In the marketplace of ideas, Leonia has decided it pays to advertise. The town is selling an education in its public schools through a direct-mail blitz of several neighboring communities. A handful of public school systems in the metropolitan area, such as Greenwich, Conn., accept tuition students from outside the district. But advertise for them? Officials in the education circles of New Jersey, New York and Connecticut say they never heard of it, at least until now. Leonia believes the unusual strategy holds the answer to declining enrollment and potential reductions of teachers and courses - problems faced by scores of suburbs. Each out-of-town student would shore up enrollment and do so at a tuition ranging from $1,300 to $4,000, enough for Leonia to break even. The district does not receive state aid for the outside pupils.

Two account executives, who were responsible for supervising the 24-hour trading desk that Dean Witter Reynolds Inc. opened in January, used a phony account to make at least $80 million of unauthorized trades yielding them more than $600,000 in profits, according to criminal charges filed yesterday with Federal District Judge Charles S. Haight. The papers, filed by United States Attorney Rudolph W. Giuliani, said the two registered commodity account executives, Shukry Mishrick and William Fellus, had misused their supervisory positions on the desk to engage in unauthorized commodity trading. The executives were accused of falsifying Dean Witter's trading records while crediting their profitable trades to an account they established in the name of Nessim Yaffe. According to Earl Nemser, the lawyer representing Dean Witter, Mr. Yaffe is a friend of Mr. Fellus and apparently had no knowledge of the account. Neither of the account executives disclosed their interest in the profits of the Yaffe account to Dean Witter, the papers said.

Education is emerging as a major issue in the 1984 Presidential campaign, and so far the debate is being shaped by President Reagan and Walter F. Mondale, the Democrat who is expected to win the endorsement of the nation's largest teacher organization. Mr. Mondale has delivered two major speeches attacking what he called the ''voodoo education'' policies of the Reagan Administration, hitting hard on Mr. Reagan's proposals to reduce the Federal education budget. The President has moved swiftly to establish his position in the debate as favoring a return to the basics in education and merit pay for teachers, positions that his aides say reflect a popular view. Mr. Reagan is planning a series of speeches on education, the first on Thursday in Hopkins, Minn., at a regional forum to discuss the report of the National Commission on Excellence in Education. It was that commission, created by the President, that brought the issue to the forefront of the political debate with an urgency not felt since the first Soviet space satellite shook American confidence in its public schools in 1957. In its recent report, the commission found a ''rising tide of mediocrity in the nation's schools'' and called for tougher academic standards, higher pay for teachers, more homework, stricter discipline and other changes in public education.

Prime Minister Indira Gandhi, speaking for the third world, warned the industrial nations today that economic recovery risked being snuffed out unless steps were taken immediately to help developing nations pay their debts and get their own economies growing again. But her view of the global economy has already been rejected in general terms by the nations that she was addressing, and this conflict threatens to become worse during the sixth United Nations Conference on Trade and Development, which opened here Monday and runs to June 30. Speaking to delegates from the 166 nations represented here, the Indian Prime Minister said: ''I am among those who believe that no sustained revival in the North is possible without the development of the South. The world is too integrated to permit segmentation.''

Wall Street is full of middlemen whose business is to bring buyers and sellers together and extract a profit along the way. In the Treasury market, the world's largest securities market, with more than five times the dollar volume of the New York Stock Exchange, middlemen have carved a special niche. Because there is no central trading floor for Treasury issues, a handful of little-known broker firms have evolved to execute trades between securities firms. ''Brokers are, in effect, an exchange,'' said Richard A. Spelke, senior vice president at the Security Pacific National Bank of Los Angeles, which owns R.M.J. Securities, a Government securities broker. ''They provide the Treasury bond market with the same service that the New York Stock Exchange provides to the equity market.'' Crucial to Bond Dealers R.M.J. and the four other major brokers in the Treasury market are crucial to the bond traders whose decisions help determine whether interest rates rise or fall. The investing public, whether a pension fund buying $100 million of bonds or an odd-lot buyer of $10,000 of Treasury bills, does business with a securities firm, but seldom with one of these specialized brokers.

E.J. Kahn Jr., a writer for The New Yorker and a strictly urban type from way back, first went to Truro, a small town now mostly snuggled inside the Cape Cod National Seashore, as a summer renter in 1949. Now, for reasons unfathomable to nearly all save him, he -along with his wife, Eleanor, and their big black Belgian Shepherd, Rainbow - spend more and more of each year in a home they own there. They didn't vacate it in 1982, for instance, until shortly before Christmas, and then only when their pump froze. In May, they returned to Truro from Manhattan, where they theoretically reside; and the following is an excerpt from Mr. Kahn's first-week journal. By E.J. KAHN JR. Sunday Crossed the Sagamore Bridge, which keeps the Cape at least somewhat aloof from the menacing mainland, at 5:52 P.M. We opened the car windows. From here on in - 50 miles to go - we know the air will be fresh. Next familiar milestone, another 28 minutes along the way, is the Orleans traffic circle, gateway to Outer Cape Cod, or Lower Cape Cod -our Cape Cod.

President Reagan announced today that he was relaxing proposals that the Soviet Union scrap a substantial part of its long-range missile force, but he said he was maintaining his goal of obtaining large reductions in missile warheads in the strategic nuclear arms talks. The President spoke at the White House as talks with the Soviet Union on reductions in long-range nuclear arms resumed in Geneva. He said that he was not changing his proposal for a limit on the number of warheads - 5,000 on each side - but that he would relax his proposed limit of 850 on the number of land- and sea-based missiles. He did not give a figure.

THE interior designer Keith Irvine remembers the magical day that marked the advent of summer when he was a child in Scotland. ''The rugs were rolled up,'' Mr. Irvine said, ''and all the heavy brocade upholstered furniture was covered with beige linen slipcovers to protect it from the sun. The whole house looked and felt different. The brocade was scratchy to sit on; the summer slipcovers felt cool, soft and comfortable.'' Although few people today perform this elaborate ritual, there is a new breed of summer slipcover making its way into city apartments and country houses. Dramatically modern in appearance, these slipcovers rely more on effect than fit and are made in an assortment of materials and shapes. While the word slipcover may conjure up the image of an old-fashioned room that Henry James would describe as ''a wilderness of faded chintz,'' many slipcovers today are being used to transform a wilderness of unmatching furniture into a cohesive interior design.

The Senate tonight approved by a vote of 55 to 43 an increase of $8.4 billion in the United States' contribution to the International Monetary Fund. The vote came after the Senate turned back a series of amendments sponsored by conservative Republicans intended to block the increase. The House still has to act on the I.M.F. issue. Legislative aides said the bill might run into greater difficulty in that chamber and that final passage would be determined by the amount of pressure President Reagan is able to bring to bear.