I also attempted to use the system.date token. Problem their was I cannot break it down to just year. I would like to use a token but haven't figured out the easy way to do this sight wide.
Please move the thread to Products. "Community" is for website feedback, not product support -- and yes, this is confusing!
Like Greg says, all LPs have templates. Mostly empty perhaps, but they have to be there.
On Free-Form LPs (I assume that's what they are, not Guided LPs, if it's a sufficiently old system) you can add an HTML Element to the canvas.
+1 on Sanford.
The main difficulty is how are you going to add a JS to a Marketo LP. You will have to do it either in the LP or simply add a token to the LP template, then add this same token to the program hosting the LP and add the JS the token.
Forgot to mention this is for Guided LP templates. On free-form, as pointed out by Sanford, just add an HTML element.