[en] We apply for the first time the time-dependent convection (TDC) treatment of Gabriel and Grigahcène et al. to the mode identification and seismic study of delta Sct stars. We consider the influence of this treatment on the photometric amplitude ratios and phase differences, and compare our TDC results to frozen convection (FC) results. We also compare the results obtained with different values of the mixing-length (ML) parameter alpha. Finally, we identify the modes and perform a seismic study of the stars V784 Cassiopeae (Cas), 1 Monocerotis (Mon) and 28 Andromedae (And), and show that our TDC models agree better with observations than FC models.