Abstract Here we describe a new program, written in Octave version 4.2.1, freely available to run in both Linux and Windows systems, called ZTR.m. ZTR.m is one of a series designed to exclusively mimic and model quasielastic neutron scattering (QENS) data on water, ranging from that confined in nano-pores to bulk water. This program promptly allows for visualising initial fitting results, including modelling of the experimental spectra and evolution of the diffusion coefficients vs scattering vector, Q. As example, QENS spectra obtained using the time of flight spectrometer PELICAN at ANSTO from a clay that has been stored over a saturated solution has been used to demonstrated how ZTR.m correctly describes the dynamics of water in confinement.