PLAN 9 FROM OUTER SPACE is a 1957 movie?

Plan 9 from Outer Space (aka Grave Robbers from Outer Space) is not a 1959 movie. It was distributed by DCA in 1958, and had a public release in June [https://archive.org/details/filmbulletin195826film/page/n462/mode/1up?view=theater&q=%22Plan+9%22]. The private screening which took place at the Carlton Theatre in Los Angeles on March 15, 1957, is known from the interviews and private comments from the cast and crew members of this movie -- they are quoted by Rudolph Grey in his book "Nightmare of Ecstasy: The Life and Art of Edward D. Wood, Jr." [https://archive.org/details/nightmareofecsta00rudo/mode/2up]. The time and place of the screening was not announced to public. The only known third party, other than the film crew, who was present at that screening by private invitation was Forrest J. Ackerman [nm0009969], then the founding editor and principal writer of the magazine Famous Monsters of Filmland [https://archive.org/details/Nebula_Science_Fiction_020_1957-03_LennyS-cape1736/mode/2up?q=%22Grave+Robbers+From+Outer+Space%22 ; https://archive.org/details/Famous_Monsters_of_Filmland_003_1959_Teachbug-Sprout/page/n15/mode/1up?q=%22Grave+Robbers+From+Outer+Space%22]. According to IMDb rules, the market screenings that are by private invitation only, as well as any occasional show to non-public focus groups to assess audience reaction before making final edits, are not considered public releases, therefore should not be considered as release dates [https://help.imdb.com/article/contribution/titles/release-dates/GVUUDEPJNAW6G35P#guidelines]. In light of the above, I suggest: 1) Add a trivia about the preview screening at Carlton Theatre, Los Angeles (15 March 1957); 2) Add a release date June 1958 with attribute (In a limited number of cinemas); 3) Delete the release date 15 March 1957.