You can try Time Slot Reservation by Fabien Felix

http://joomlacode.org/gf/project/blood_collect1/

Originally designed for registration to blood collections, the component has been extended to any type of time slot
based sessions such as: volunteers organizing events, registrations with a limited amount of attendees per session,
ressource reservation (such as tennis course).
It provides an easy way to create locations, events, iterative sessions within an event from the front-end, and
register to a session, including email confirmations, reports, statistics, integration with Google maps, security
with private codes and image recognition.