Colorscale shows seconds instead of DateTime

I'm not sure how Igor recognizes some DateTime waves and recognizes others as simply double precision waves. By this I mean that some DateTime waves show up in the proper format when edited, and others show up as a number of seconds when edited. When attempting to color a plot by DateTime, this issue becomes more than an idle curiosity. If Igor, for whatever reason, does not intrinsically recognize the DateTime wave used to color the plot, number of seconds is all that will show up on the Color Scale. Does anyone know how to format a DateTime wave properly to avoid a Color Scale labelled by number of seconds? I seem to have exhausted my options.