Joe DiMaggio kept a diary. Think of that for a moment.

The private DiMaggio — who spurned millions of dollars to write a tell-all autobiography but not the riches derived from signing bats or balls — dedicated parts of many days from 1982 to 1993 to recording his activities in a flowing script. You can almost imagine him at day’s end, maybe with his tie still knotted but his blazer hanging in the closet, summarizing his day.

It is not a juicy personal journal. Meals with pals, not his romances, were cited as he moved from his late 60s to his late 70s. A sampling of the entries showed pages filled with mundane details and occasionally interesting detours. They were set down on hotel and airline stationery, plain white or yellow legal paper, but never on personal letterhead. He ended entries as if submitting them for reimbursement: by itemizing his expenses.

“He’d bring them into my office, hand them to the office manager every month and say, ‘Tell Morris there’s good stuff in here for his book,’ ” said Morris Engelberg, DiMaggio’s lawyer. He added: “These writings really show who he is. He’s just a plain old Joe.”

Engelberg recently sold the collection of nearly 2,500 pages preserved in 29 binders to Steiner Sports. At a news conference today at Gallagher’s Steak House, one of DiMaggio’s favorites in New York, Steiner is expected to announce its plans to auction the trove in its entirety or page by page.

“We’re listing it at a minimum $1.5 million bid,” said Brandon Steiner, the chairman of the company. “To get a whole page of a guy’s handwritten notes, you have to believe each page is worth $2,000 to $5,500 each.”

What Steiner eventually gets is almost tangential to the almost voyeuristic look at the particulars of DiMaggio’s life.

He wrote down when he woke up, flight numbers and boarding times.

If he took a steam bath, he took note.

On Dec. 12, 1983, he visited his accountant. “Mr. Coffee made me an offer and we discussed at length what my counter bid should be,” he wrote.

There were breakfasts at the Stage Deli in Manhattan with pals.

Lunch with Mayor Edward I. Koch at the Waldorf-Astoria Hotel.

The dedication of a baseball field at the Virginia Military Institute.

He described a day in April 1986 when he made appearances in Rego Park, Queens, and Manhattan for the Bowery Bank. “Went to lobby — signed pics — autographs and conversed with customers,” he wrote.

At the conclusion of his unemotional recollection about receiving the Medal of Honor from the Liberty-Ellis Island Foundation on Oct. 27, 1986, he added: “Missed the last game of World Series. Back to Hasbrouck Heights hotel at 10 p.m. Saw the end of baseball on T.V.”

There is nothing about Marilyn Monroe.

DiMaggio was at the White House on Dec. 8, 1987, for the signing of the treaty banning intermediate missiles by President Ronald Reagan and the Soviet leader Mikhail Gorbachev. DiMaggio wrote that he was up at 6:30 a.m. and arrived at the East Gate in a limousine driven by a man named Leroy.

“An historic time,” DiMaggio wrote. Then: “Left White House lawn at 11:15 a.m. Went out and shopped for a tuxedo shirt as I have lost so much weight my neck size is 15 ½. Spent a couple of hours trying to find one.”

Later, on stationery from The Jefferson, a hotel in Washington, he recorded that he was one of 130 guests at a state dinner, flanked at the “number 10 table” by Maureen Reagan, the president’s older daughter, and Helena Shultz, the wife of Secretary of State George P. Shultz. “Had a good dinner and conversation with both ladies,” he said. Then, after dinner, the guests listened to Van Cliburn play piano. “Mrs. Gorbachev requested a song and Mr. Gorbachev sang some of the words from his chair,” he wrote.

DiMaggio was back in his hotel room by 11:30 that night, and on the second sheet of his entry, he wrote, “Food, tips, taxis, etc. $70.00.”

The entries illustrate DiMaggio’s frustrations with fans and current and former major leaguers who wanted his autograph.

From Anaheim, Calif., on July 8, 1989, he wrote: “Swamped with the signing of baseballs — pictures — radio and TV. Stress too much.”

Six days later, he described the “zoo” at Old-Timers’ Day at Yankee Stadium: “Must have signed at least three hundred for Old Timers — present-day players and everybody that was in the clubhouse — and it was packed.” Then: “It no longer is that people want one ball signed. All have two, three or four. Even Sparky Anderson sent a dozen over for me to sign.”

On April 30, 1991, he wanted to relax at Kennedy Airport before a flight to Miami, but he wrote: “I was asked for another autograph — just one interruption after another — people must think I have skin like an armored plate. Will get a checkup and find out how I’m holding up.”

He chafed at the benefits piling up early in 1991 to honor the 50th anniversary of his 56-game hitting streak. “If I thought this would be taking place due to the streak,” he wrote on Jan. 14 with sarcasm (or was it disdain?), “I would have stopped hitting at 40 games.”

Expenses: $46.