Lost Day

a.k.a. Eight Burrs
Designed by David Bruce, made by Interlocking Puzzles 2000.
(wood, 24 pieces, 4.8 inches)

The basic idea is to combine two eight piece assemblies and then add eight "outer" pieces. Here are diagrams of the pieces from the solution that came with the puzzle:

Assembly A pieces:

Assembly B pieces:

Outer pieces pieces:

Further Reading
Lost Day solution that was sold with the puzzle (pdf 9 pages).