An ordinary man somehow ends up with the appointment book of some kind of international arms dealer. He starts going to the arms dealer’s appointments, but nobody shows up.
Thanks in advance!
It could it be “The Passenger”:
The Passenger (Professione: reporter) is a film directed and co-written by Michelangelo Antonioni, released in 1975, in which Jack Nicholson stars as a reporter in Africa who assumes the identity of a dead stranger. The film competed for the “Palme d’Or” award at the 1975 Cannes Film Festival.
After deciding that his own life wasn’t worth living anymore, he switches identities with the dead man, taking the man’s passport (with his own photo swapped in), his luggage, and his appointment schedule.
BRILLIANT movie, with one of the most astonishing single-shot scenes ever accomplished, and that rarest of things in movies: a perfect ending.