Multiple values on plot_date

I am trying to plot multiple values on a date plot. plot

    > allows for this but plot date tells me it only takes 5
    > arguments. Is there a reason for this difference? Am I
    > using the function incorrectly? Does anyone know of a work
    > around? The exception is below:

You are using it correctly -- plot_date doesn't support multiple x,y
pairs; many plot functions do not, plot is more of an exception than
the rule here. plot_date could pass the arguments straight through to
plot, but this would break the default fmt argument ('bo') that
plot_date uses, which is different than the one plot uses.