Jirachi: Wish Maker
This movie was released as the anime was airing an arc of episodes in which Ash and friends stayed in Slateport City. The movie occurs outside of any built up area, so it’s pretty certain this is not a correct placement.
The anime movie map shows that the movie takes place just south of
Fallarbor Town, so it would make sense for it to take place around the same
time as May’s Pokémon Contest there. However the absence May’s Skitty suggests
it probably takes place prior to AG047. The solution that seems to
fit best is that it took place during a detour south on the way to Fallarbor
Town.
This leaves a window of possibility between AG040 and AG047. Given
the location’s proximity to Fallarbor Town, the later in that leg of the
journey, the better. Thus ideal placement seems to be just prior to AG047.
Source: Bulbapedia
