To set x-variable:

Choose your x-variable, representing either time or space. If that variable is formatted as a date in the native file, check box 'x is date' and indicate which is the native format of x. By default, the format is set as %Y-%m-%d : dates like '2015-10-25' should be reckognised.

Here are other examples of dates format:

For more detail about date formatting, please consult the Details section of the R function strptime here

To set y-variable(s):

Choose your y1 variable. It is the series you wish to analyze through wavelet-based methods.If you have a second variable that you wish to analyze along the first one, check box 'Add y2 variable' and then select variable.