All issues were cover dated as Week Ending (their pull date), with their on sale date 7 days prior, except for #86, which went on sale only 3 days before #85's pull date.
Comic was on sale Saturday from #1 ~ 85; from #86 onwards it was published on Wednesday (prior to its merger with Dracula Lives) until the end of publication.
Merges with Dracula Lives (Marvel UK, 1974 series) #88 (June 23, 1976).
Merges with Mighty World of Marvel (Marvel UK, 1972 series) #231 (March 2, 1977).
A promo in The Mighty World of Marvel #109 (week ending November 2, 1974) states that Planet of the Apes is "on sale every week."