Olshevsky's Marvel Time

To allow their characters to stay evergreen, both Marvel and DC have established "sliding timelines" so that the present is always today, and modern Heroic Ages of their respective universes are only 10 or 15 (or some less specified number) of years old.

As I've mentioned before, this was not always the case. George Olshevsky's Marvel indices argue that in the early years, Marvel seemed to preceded in real time. Will most are unfazed by this, at least this guy thinks it ruined the Marvel Universe. While I wouldn't go that far, I do think there are certainly tradeoffs. The eternal present comes at the sacrifice of allowing characters to truly grow and inevitably means big changes are impermanent.

Anyway, here are the "Marvel Years" as outlined by Olshevsky. He measures them by years in Peter Parker's life. The actual calendar years are my addition and relate the most likely real-world translation (if your were inclined to do that) based on the time of publication.

YEAR ONE [1960-1961] (PP-HS-SophY):
June*- FF spaceflight.
Sept. - Peter Parker is a junior in high school.
Winter – the FF #1.
(Hank Pym in the Ant-Hill) (The Hulk)
Spring (March-April) – Peter Parker becomes Spider-Man [Aug 62]
intro Thor
debut Ant-Man

YEAR TWO [1961-1962] (PP HS-JunY)
debut Wasp
Intro. Dr. Strange

YEAR THREE [1962-1963](PP HS-SenY):
Sept. – PP is a senior in high school.
Sept. – The Avengers form.
Oct. – The X-Men go public. [Sep 63]
November – Ant-Man becomes Giant Man.
mid-Dec. – The Black Widow first appears.
March – Iron Man fights Hawkeye and Black Widow.
May – Reed and Sue engaged. Johnny and Ben almost meet the Beatles.
June – Hawkeye joins Avengers. PP and JS graduate High School. Quicksilver and SW join the Avengers. Reed and Sue marry. Nick Fury named director of SHIELD.
July – Galactus arrives. Sentinels. Quentin Quire is born.

YEAR FOUR [1963-1964] (PP-CY-1):
Peter Parker’s freshman year of college.
Winter- Captain Mar-Vell arrives.
Feb. - Bobby Drake (Iceman) turns 18.
Late May-early June – 1: Lorna Dane
Summer. Franklin Richards born.

YEAR FIVE [1964-1965] (PP CY-2):
September. The Vision is created. Hank Pym and Janet Van Dyne are married.
Late Sept-early Oct – 1: Sunfire
June-July: Hank McCoy goes to work for Brand Corp

YEAR SIX [1965-1966] (PP CY-3):
October – Beast gets furry.
May – GXM#1. The New X-Men

YEAR SIX [1966-1967] (PP CY-4):
Sept – Thunderbird dies.
Jan – Jean Grey replaced by Phoenix.

If Jean Grey was 24 when she is presumed to have died (based on the dates on her tombstone), and she is the same age as Peter Parker, then she must have died around 1968-69.