A federal judge here ruled yesterday that daily "records of schedule" of Alexander Haig's activities while secretary of state -- which include summaries of logs detailing his incoming telephone calls and all meetings -- are covered by the Freedom of Information Act and must be turned over to The Washington Post.

U.S. District Judge John Lewis Smith Jr. ordered the State Department to give the daily summaries to The Post within 30 days or provide him with exact reasons for deleting portions of the documents.

Scott Armstrong, a former Post reporter who requested the documents, said the ruling is important because it affects "exactly the documents that some government officials . . . don't want to be in the public domain."

"In many cases, these are the only records of those meetings," Armstrong said.

The State Department said it had no comment on Smith's order. Post officials said that they had not yet seen the opinion.

Armstrong, who now heads the nonprofit National Security Archives, said his request for the daily summaries of Haig's activities grew out of a long-term project by the newspaper to examine how foreign policy decisions are made. He said he previously had requested similar materials from members of the Carter administration and was provided the documents within weeks.

When Haig resigned on June 25, 1982, Armstrong said he immediately asked for all documents, including telephone message slips, meeting logs and personal calendars, that chronicled Haig's daily activities.

Armstrong said he learned later that department officials held numerous meetings to discuss how to avoid turning over the documents and advised Haig to take them home with him. Haig subsequently gave the documents to the Library of Congress, but ordered them sealed for a long period of time.

Armstrong, on behalf of The Post, then requested the State Department's copies of the same documents, saying that they were agency records and subject to the FOIA. The department denied the request on the ground that they were the secretary's "personal work aids" and were not covered by FOIA. The Post then filed suit to gain Haig's records.

After a 1984 ruling in another case found that telephone message slips and calendars were not covered by the FOIA, Armstrong and The Post continued to seek the "records of schedules" kept by two Haig aides that summarized the daily telephone and meeting logs.

State Department lawyers argued that the records were official agency records because they were filed away and never again used. But Smith noted that all government agencies produce "reams of documents on any given day that are subsequently filed and forgotten."

" . . . The importance of the materials to agency operations is . . . readily apparent from the fact that agency employes have taken the time and effort to generate, compile and store the documents for possible future reference," Smith said.