At some point during her 12-year tenure as a bus driver, Peg’s students give her the nickname, Baby Driver, based on the “beloved action film of the same name”. Peg notes that she “was already fifty” when she was given the nickname.

Baby Driver was released in the U.S. and the U.K. on June 28, 2017.

Peg claims her bus “black ice” accident happened in February. She heard the Lumon ad on the radio, was off work the next day and visited the Lumon site.

New office, big building looks like a mall. Peg refers to this as, “a few years back”.

Peg writes that she worked at Lumon for 2 years before she and her innie, Peggy, started passing notes. Peg and Peggy pass notes for 3 or 4 weeks before innie Peggy finishes the Lexington file.

Big deal in the office.

Date is in the text of a printed and scanned letter so it could be human error.

Peg mentions it in the “Saturday, November 10” letter to Daria, “I saw your thorough coverage of the Dorner truck incident on November third.”

Peg doesn’t add “last year”. This is typically how someone would refer to something that happened very recently.

Peg writes that later that same night of Fri, Nov 3, she is watching TV and sees Daria Thorne report that the Dorner Therapeutics truck had been blown up in New York at 2:32 pm that day.

Peggy replies, “Not much, she said, other than it being very important work.”

Peg sends Peggy a note telling her about the truck explosion. Peg also tells her not to refine any more numbers.

Three days pass with no reply. The days turned to weeks with no reply.

One Tuesday, date ambiguous, Peg emerged with wet hair and found a note from Lumon on her windshield claiming her innie had a painless mishap with a water cooler.

Weeks after the truck explosion and two weeks after the wet hair incident, Peggy sends the handbook and a note in plain English, “been in Break Room. Code detectors down today. I think you’re right about Lumon.” Peg doesn’t hear from Peggy for another week.

From the letter, “Last Friday”, Peg sent a note down and came back up a few minutes later with a note in her mouth. “Peg, Leave now. Get somewhere safe. They will try to follow. Nothing they say is real. Distribute the training booklet. Answers are there if you look.”

Peg calls Mr. Alvarado and quit “on the spot.” Peg “left Topeka without returning home.”

Header date is on a printed letter, scanned to attach to email so date could be human error.

Hired by Lumon “about two years ago” in February.

Peg writes that she is staying in motel, feels like someone has been watching her, black cars are always parked near hers, and “my mail has been all crumpled when I’ve gotten it at night like someone’s been digging through it.”

Email from Jim Milchick to Daria on Nov 13 quotes Peg's obituary, indicating that she'd “passed away from complications from a car accident on November 11th.”

Day is not mentioned.

Milchick dismisses the letter and tells Daria to “focus on the high school basketball playoffs”.

Kansas high school boys and girls basketball playoffs are typically in or around March not November. Topeka, Kansas highschool basketball playoffs have been in March.

Source: Email from Jim Milchick to Daria Thorne on obit.

In a Reddit AMA on April 21, 2022, Severance creator and executive producer Dan Erickson said:

…keep in mind, Lexington Letter may be set some years before.

For male athletes in the United States, the National Basketball Association (NBA) regular season runs October-April, with the playoffs extending into June.

US high school basketball starts end of Oct to mid Dec. In 2022, Kansas high school boys and girls basketball starts Dec 1 with playoffs in March, 2023.

source:

High school basketball: When does each state begin the 2022-23 season?