The methods discussed in this paper are based on time-staggered schemes which are made unstaggered by means of an interpolation procedure. The advantages of time-staggered schemes are discussed, and it is shown by theoretical arguments and numerical experiments that the proposed interpolation method can be used without any serious loss of accuracy. For every short waves the interpolation will cause a retardation which results in greater stability and allows longer time steps. Due to their simplicity, combined with relatively high efficiency and stability, the schemes seem to provide an interesting alternative to existing methods.