You likely want a Relative Date filter. Use your [Trading Date] field as the source.
Right-click-drag that field into the Filters shelf and select "Relative Date" from the pop-up menu.
Is that what you're looking for?
Kind of, does exactly what I want...but i need the user to be able to control it from presentation mode.
Clicked 'Show Filter' and worked, so simple haha!
Thanks for help Michael!