Hi Farah, there are multiple varieties of 1-D wavelet transform. There is the redundant variety like MODWT where there are as many coefficients as the original data at each level. In this case the time stamp of the coefficients are the same as the data.
In the critically sampled DWT (wavedec), the coefficients are spaced in time proportional to the level.
Can you give a concrete example of which wavelet transform you are trying to use? It would be helpful to give us a sample signal and the sampling rate of the original signal.
