What was going on when I was born?

The rate of unemployment in April, remainedat the March level of 10.1 percent of the labor force, but the nation's employment situation ''improved considerably,'' the Labor Department said today. Dr. Janet L. Norwood, Commissioner of Labor Statistics, said the data showed there had been considerable improvement in the labor market. ''Employment rose, particularly in the hard-hit manufacturing industries,'' she told the Joint Economic Committee of Congress. ''Equally important, the average number of hours worked last month expanded sharply and the amount of overtime increased.''

The operator of the Salem nuclear power plant in southern New Jersey was fined $850,000 by the Nuclear Regulatory Commission today for violations of Federal nuclear safety regulations. It was the largest fine ever imposed on a nuclear plant operator for safety deficiencies. The Public Service Electric and Gas Company, the operator of Salem, has 30 days to pay the fine, appeal it or seek a reduction. A spokesman for the utility, Bryan Smith, said officials wanted to take ''some time'' before deciding what to do.

The Israeli Cabinet voted today to accept in principle a draft agreement with Lebanon on border security and mutual relations. The accord is intended as a basis for the withdrawal of Israeli forces from Lebanon, provided the Palestine Liberation Organization and the Syrian Army also leave. Security in Southern Lebanon The agreement would provide for intimate involvement by Israel in security operations in southern Lebanon. But without a Syrian and P.L.O. pullout, the Lebanese-Israeli accord will probably not go into effect.

County officials in the area around the Indian Point reactors said yesterday that they did not plan to take any additional steps in response to the threat made by the Nuclear Regulatory Commission to shut the nuclear plants. State and Federal officials said, however, that they planned to meet in Albany next week to discuss how they could avert a shutdown. The N.R.C. threatened Thursday to close the two plants on June 9 if progress was not made in resolving ''significant deficiencies'' in emergency evacuation plans for Westchester and Rockland Counties. The leaders of the two counties said yesterday that they had been working for months to correct these defects. They said they hoped to have solutions in hand by the end of the year, but not by the commission's deadline.

The Interior Ministry said today that examination by state archivists and tests by police laboratories had determined that volumes purporting to be Hitler's secret diaries were forgeries. After initially resisting the weight of the official findings, Henri Nannen, the publisher of Stern, which had started to serialize the diaries, tonight also pronounced them a forgery and promised to expose their authors. In a television interview in his Hamburg office, he said: ''We are going to uncover the full story of this forgery and lay it before our readers. We have reason to be ashamed before our readers.''

The Senate Select Committee on Intelligence approved a measure today that would enable Congress to cut off future financing for covert operations in Central America. The cutoff would take effect if the President failed to submit a plan for the region that met with the approval of the Congressional intelligence committees. But the committee, in a bipartisan vote of 13 to 2, approved the continuation of covert activities in Central America through this fiscal year, which ends on Sept. 30. The action marked the first time that one of the Congressional intelligence committees had formally asserted what it considered its right to approve specific covert activities, according to a member of the committee.

The Government could make more than $220 million on Chrysler Corporation stock by exercising a right to purchase the stock at less than half the current market price. But company and Government officials said today that Chrysler now wants to cancel the arrangement. The deal was made in 1980, when the Government agreed to guarantee up to $1.5 billion in loans to the auto maker. Chrysler needed the loans to survive and could not obtain them without the Federal guarantee. In return for that guarantee, the Government obtained warrants to buy 14.4 million shares of Chrysler stock directly from the company at $13 a share.

Senior Lebanese officials said today that Syria had informed them that Damascus objects to virtually every major clause of the withdrawal agreement worked out between Israel and Lebanon by Secretary of State George P. Shultz. In Damascus, Syria's state-run radio denounced the agreement, saying ''any reading of the draft agreement shows that Israel has achieved military and political goals that it failed to achieve through its invasion of Lebanon.'' However, Lebanon's President, Amin Gemayel, indicated in a speech that he would not be deterred by Syrian objections. His remarks came a few hours before the Israeli Cabinet announced its agreement in principle to the draft withdrawal agreement.

Even though this country has seen a long war, a famine and then an invasion by Vietnam, this capital seems surprisingly cheerful. There are cars on the streets, food in the markets and more smiles than a visitor might expect. Small shops have been opening, and some of the proprietors seem sufficiently confident of the future that they are putting up new brick walls, windows, gates and awnings. Sometimes the awnings are temporary - quick bowers for wedding parties, of which Cambodia seems to have an inordinate number.

The High Court ordered The National Times today to stop publishing classified documents that assert that Australia spied on Asian allies and was cut off from United States information on China's invasion of Vietnam in 1979. The articles in the weekly newspaper include charges that Australian intelligence agents monitored telephone calls in allied countries and conducted secret raids for politically damaging information at home. The injunction was sought by Prime Minister Robert Hawke's Government but came too late to bar the first installment on the operations of the Australian Security Intelligence Organization. Mr. Hawke, while conceding that some of the charges were true, said publication threatened national security.

The official English-language China Daily is to publish a North American edition starting June 1, the newspaper said today.

China, embarrassed by the first successful hijacking of one of its civil airliners, today dispatched an official delegation for discussions with authorities in South Korea on the return of the hijackers as well as the plane, its crew and passengers. Shen Tu, the director of the China's Civil Aviation Administration, left for Seoul with the delegation at 8 A.M. aboard a special plane. It will be the first such face-to-face meeting between the Chinese and the South Koreans, who were enemies in the Korean War. The two countries still do not have diplomatic relations, since Peking recognizes only North Korea, but they have quietly conducted trade through Hong Kong and other Asian countries.