Date of FF origin

[wolframbane]

Does anyone happen to know of any date reference as to when the events of Fantastic Four #1 (1961), their first encounter with the Mole Man and start of the Modern Era, and the flashback, their Marvel-1 spaceflight where there gained their powers, had occurred? I have a few bits of info, but are there any I missed?

In Thing #10, it is mentioned the spaceflight took place in Autumn.

In Human Torch #1, it is mentioned the spaceflight, their encounter with Mole Man, and at least one alien encounter (probably the Skulls in Fantastic Four #2) occurred during Johnny's summer vacation before his Junior year at high school.

Fantastic Four Season One #1 has the spaceflight occur in June, but this story is non-canon.

Marvel Saga #1 and Marvel 75th Anniversary Celebration have a series of one panel appearances showing what other Marvel characters are doing on the same day as the spaceflight, including:
Major Carol Danvers observes the launch of the Marvel-1
The frozen form of Captain America is located and worshiped by an Eskimo tribe.
The amnesiac Namor wanders through New York City.
Colonel Nick Fury considers leaving the CIA, informing Dum-Dum Dugan (LMD) of rumors of a new organization being formed.
Tony Stark dates two women. At a hotel, Pepper Potts informs him that Ho Yinsen is at the same hotel.
At Gamma Base, Thunderbolt Ross berates Bruce Banner, who later has a picnic with Betty Ross.
Hank Pym is ready to test the subatomic particles he dubs "Pym Particles."
Jane Foster tells Donald Blake he needs a vacation, and he considers traveling to Norway.
Charles Xavier trains Jean Grey in her telekinesis. Charles later speaks with his students Scott Summers, Bobby Drake and Hank McCoy at Xavier's School. Warren Worthington practices his flying.
Dr. Stephen Strange returns from his travels and decides to purchase his Sanctum Sanctorum in Greenwich Village.
Matt Murdock and Foggy Nelson study to begin their careers in law. Matt later works out in the boxing ring at Fogwell's Gym.
Peter Parker reads a newspaper about Reed Richards while taunted by Flash Thompson. He later shows his Uncle Ben his photography.
Winter Soldier is within suspended animation and a black widow spider crawls nearby.
The young Sam Alexander watches an episode of The Rawhide Kid.
Doctor Doom puts down an insurrection in Latveria.
Carl Lucas remains incarcerated in prison.
Logan hunts in the wilderness with his adamantium claws.
In K'un-Lun, Lei Kung trains with Daniel Rand, and will inform the Elders that Daniel is ready to face Shou-Lao the Undying.
Millie Collins models for a photo shoot.
The young Ororo walks across an African plain.
The young Kamala Khan plays in her backyard before her mother calls her in.

Some interesting notes about these.
The novel The Avengers: The Man Who Stole Tomorrow (Marvel Novel Series #10) by David Michelinie mentioned the day the Eskimos found Cap was in Fall.
Hank McCoy was shown with Charles Xavier, Scott Summers and Bobby Drake the Xavier's School. Hank was recruited in to the X-Men by Scott, Bobby and Warren Worthington, who was previously the costumed hero Avenging Angel. Thus the costumed Avenging Angel preceded the events of FF #1, and technically was a public hero before the Fantastic Four. But it appeared a combination of never being noticed and early retirement as the Avenging Angel caused Warren to go unrecognized.

[StrayLamb]

There was a discussion of dates for this period beginning over here. Hope it helps!

[wolframbane]

Much appreciated!!