What was going on when I was born?

Argentina's newly elected Government, seeking breathing space to repay the developing world's third-largest foreign debt, asked its foreign creditors today if it could defer for six months payment of the more than $12 billion that is due in that period. The Government of President Raul Alfonsin, which inherited a $40 billion foreign debt when it took over five days ago, asked a steering committee that represents more than 300 international banks to defer until June 30 the refinancing of nearly $9 billion in debt that was due today. In meetings with bank representatives here and in a telex to the 12- member steering committee in New York, Economics Minister Bernardo Grinspun also asked to put off the payment of nearly $3.5 billion in both overdue interest and new interest that will be due by then. Reactions Mixed The reactions of representatives of the steering committee of American, European and Japanese banks was mixed. They said in interviews that the committee would likely recommend that Argentina's creditors put off the refinancing that was due today but not put off all the interest payments. ''The new Government is being responsible and realistic,'' said one of the representatives. ''It's clear they cannot pay all the interest, but we can't waive it all for six months.''

An article in Sports Pages on Saturday about a three-year contract between the National Basketball Association and its referees incorrectly described the new pay scale.

In the rectory of St. Paul's Church in East Harlem yesterday, Sister Joan Hart took another step toward bringing the Roman Catholic bishops' recent pastoral letter against nuclear arms to the attention of priests working in the field. Sister Hart, who has carried out similar missions in dozens of parishes in the archdiocese since late fall, talked about the letter to nine priests from parishes in the area. Then she asked what she could do, as the head of the archdiocesan office of justice and peace, to help them raise the issue with their parishioners. The priests said the task was difficult in East Harlem because the agonies of daily life often made cosmic issues such as war and peace seem irrelevant. 'Living in the Ruins' ''The bomb has already gone off,'' said the Rev. Ray Byrne, the host pastor. ''Money has been drained away from the poor to build nuclear missiles. We're living in the ruins.''

A picture caption on Wednesday, with an article on the police in Spain, misinterpreted a banner at a police union office. It called for discussions with Interior Minister Jose Barrionuevo.

The last 190 men of the United States combat force in Grenada, along with their commanding general, flew home today, an American spokesman said. That left about 300 American noncombat soldiers to support Caribbean peacekeeping forces here. ''We leave with a great deal of confidence that things are going to be good in Grenada,'' said the commander, Maj. Gen. Jack B. Farris, before trotting across the Cuban-built airstrip at Point Salines to join his men on the C-141 transport plane. ''We wouldn't be leaving if we didn't think the security situation was good.''

The United States battleship New Jersey fired its five-inch guns today in support of marines who were under attack from Moslem Druse militia positions in hills overlooking Beirut. It was the second day of action for the battleship, which fired 16-inch shells Wednesday at Syrian antiaircraft positions in mountains 12 miles or more to the east. Earlier, members of the French and British contingents of the multinational force were also attacked. Two French soldiers were killed and three others wounded, and a rocket struck a building next to the headquarters of the British contingent south of Beirut.

The GTE Corporation announced yesterday that it would drop the monthly service fee it charges users of its long-distance Sprint service on Jan. 1 and replace it with a minimum monthly charge of $5. Sprint currently charges residential customers a flat fee of $5 a month in addition to their calling charges. The monthly fee for business customers is $25. But beginning Jan. 1, GTE said, customers will not be charged the fee if they make more than $5 worth of long-distance calls during the month.

All through the 1970's American farmers set one record after another in selling their goods abroad. Their exports of corn more than quadrupled, their wheat and soybean exports nearly doubled and they captured three-quarters of all the worldwide growth in agricultural trade. The United States took to calling itself ''the breadbasket of the world,'' and the nation's superefficient farmers stepped up their production to meet the multibillion-bushel grain orders of countries such as the Soviet Union, India and China. But foreign markets proved unsteady. President Carter limited sales to the Soviet Union after the invasion of Afghanistan. Orders began to slide with worldwide recession, and American farmers now find themselves locked into a cycle of overproduction, falling prices and dependence on Government subsidies.

''Perhaps the greatest myth surrounds the President's attempt to fight poverty without resorting to the rubber bullets and blank checks that were enlisted in similar wars in the past.'' - Edwin Meese 3d. (A26:4.)

Mayor Koch said yesterday that agents of the Federal Bureau of Investigation went to City Hall last week seeking to learn his source for a translation of a Lebanese newspaper article that sparked a long-running dispute with Secretary of Defense Caspar W. Weinberger. The agents were not told the source of the translation, which was of an account of a Weinberger meeting with a high Saudi official. But yesterday, in a letter to William H. Webster, Director of the F.B.I., Mr. Koch said it was the Israeli consul general in New York, Naftali Lavie. Mr. Koch had previously denied that the Israeli Government was the source. In his letter, the Mayor also suggested that Mr. Weinberger was behind the F.B.I. inquiry and that it was really an attempt ''to use the F.B.I. to stifle my constitutional rights to comment upon matters of national policy.''

A Company News report in Business Day Wednesday on Gulf and Western Industries misstated factors reflected in its earnings in the fiscal year 1983. Earnings excluded special gains and charges.

The Crocker National Corporation, the nation's 12th-largest banking organization, said yesterday that it will report a loss of about $57 million for the fourth quarter and a loss of about $10 million for the entire year. Crocker, which for years has reported poor earnings relative to other major bank groups, attributed the expected losses primarily to unfavorable real estate and agricultural loans. The San Francisco-based group earned $17.8 million in the 1982 final quarter.