  The ANTARES neutrino telescope is currently being constructed in the
Mediterranean Sea. The complete detector will consist of 12 strings,
supplemented by an additional instrumentation line. Nine strings are at present
deployed of which five are already connected to the shore and operating. Each
string is equipped with 75 Optical Modules (OMs) housing the photomultipliers
to detect the Cherenkov light induced by the charged particles produced in
neutrino reactions. An accurate measurement of the Cherenkov photon arrival
times as well as the positions and orientations of the OMs is required for a
precise reconstruction of the direction of the detected neutrinos. For this
purpose the ANTARES detector is provided with several system s to facilitate
the calibration of the detector. The time calibration is performed using light
pulses emitted from LED and laser devices. The positioning is done via acoustic
triangulation using hydrophones. Additionally, local tilt angles and the
orientations of the modules are measured with a set of tiltmeters and
compasses. In this paper, it is demonstrated that the ANTARES time and
alignment calibration systems operate successfully in situ. In particular, it
is shown that the ANTARES read-out electronics is capable of reaching a
sub-nanosecond time resolution.
