Part of my work on the modelling of hydrodynamic effects in anchored flame combustion instabilities requires the treatment of non periodic signals with Fourier series. This is successfully performed by extending the signal over a virtual domain, and ensuring that it remains periodic within this extended domain. This is a common method for steady problems. However, for time stepping pseudo spectral methods, additional buffering techniques must be used to avoid propagation of perturbations from the extended domain to the real domain.