Time alignment of the front end electronics of the LHCb calorimeters

LHCb is the experiment at the Large Hadron Collider at CERN designed for performing studies of CP-symmetry violation and rare decays of B-hadrons. Its calorimeter system allows to trigger on photons and electrons by associating the information from a scintillating pad signing charged particle (SPD), a pre-shower tagging electromagnetic particles (PS), an electromagnetic calorimeter (ECAL) and a hadronic calorimeter (HCAL). We present the principles and procedures for the fine time-alignment throughout the commissioning and the first collision phases. We give a particular emphasis to the choices made in the electronic design of the calorimeters to deal with the signal shape and spill over. Also we summarise the achieved levels of synchronisation.