It seems the titles WHEN THE SUN GOES DOWN and IN THE EVENING (WHEN THE SUN GOES DOWN) have been used interchangeably for the song that Leroy Carr wrote. It has been recorded by The Woody Allen Trio, Count Basie, Big Bill Broonzy, The Charles Brown Trio, Bumble Bee Slim, Leroy Carr, Ray Charles, Lonnie Donegan, Ella Fitzgerald, The Ink Spots, Eartha Kitt, Leadbelly, Marian McPartland, Memphis Slim, Lou Rawls, Pete Seeger, Mel Tormé, Big Joe Turner, T-Bone Walker, Dinah Washington, Josh White, Big Joe Williams, Jimmy Witherspoon and several others.

To confuse things, other people have written songs with the same titles.

Under the title WHEN THE SUN GOES DOWN:
Kenny Chesney recorded one written by Brett James.
Rose Maddox recorded one written by Bill Mack.
Frank Sinatra recorded one written by Walter O'Keefe and Irvine Orton.
Cassandra Wilson recorded one written by herself.
Jesse Colin Young recorded one written by himself.

Under the title IN THE EVENING (WHEN THE SUN GOES DOWN):
Joe Lee Carter recorded one written by Don Raye Cahn.
John Lee Hooker recorded one that was called traditional.

The above information is from allmusic.