When Does "Return to the Batcave" (2003) Take Place?
"Return to the Batcave: The Misadventures of Adam & Burt" is a meta historical fiction comedy film written by Duane Poole that released March 9th, 2003. So when is "Return to the Batcave" set?
It takes place in the year:
We know this because when Adam West and Burt Ward update each-other on their lives Burt says, ..."I own this computer animation studio! Visual effects for movies and television." and the real-world Burt Ward started Boy Wonder Visual Effects Incorporated in 2001 AD so it must be during or after 2001 AD.

2003 AD or 2004 AD
We know this because when Adam West and Burt Ward update each-other on their lives Burt says, ..."I own this computer animation studio! Visual effects for movies and television." and the real-world Burt Ward started Boy Wonder Visual Effects Incorporated in 2001 AD so it must be during or after 2001 AD.
More specifically, Adam's car has an inspection certification expiration date sticker that reads "2003". So it must be during or before 2003 AD. The car in question is a 2003 Maserati Spyder (he mysteriously has two) and the model changed slightly in 2004. So it must be during or after 2003 AD or during or before 2004 AD.
Additionally, there are numerous flashback sequences that reveal the backstory to the casting and production of the television show "Batman" (1966). The show premiered in January of 1966 AD so the scenes depicting Adam negotiating for the role of Batman ("I'll take my chances because I love the script."), Burt auditioning for the role of Robin ("I just plan on saying my lines... Is there more to it than that?"), and their first day of shooting must take place sometime in late 1965 AD.
In another flashback, Burt and his wife sit down to watch the premiere and he says, "Do you really think anybody else is going to watch this but us?" and the show premiered on January 12th, 1966 AD. So this scene must take place in January of 1966 AD.
Eventually, the flashbacks covered scenes like Burt saying, "Can't believe we're getting canceled." and Adam responding, "Don't panic yet, it'll be months before a decision's made." the show aired its final episode on March 14th, 1968 AD. In the same scene, Burt reveals, 'I should've taken that role in "The Graduate" when they offered it to me. I could be Dustin Hoffman today.' The film "The Graduate" (1967) released on December 21st, 1967 AD. So these scenes must be after December of 1967 AD but before March of 1968 AD, sometime in early 1968 AD.
[For clarification, this story does not take place on the fictional timeline of the DC Comics universe. Nor even its alternate universes.]

