From the lists of variables I've seen, I wouldn't be surprised if there is a month of year variable. Also day/ date/ year/ short date/ long date.
Having made NCM create folders with the date in the name, I expect NPM can also leverage this capability. And that was going back a few years. I think they still exist.
Can you look here and figure out which variable name you're dealing with:
And then populate it like below (except substitute your variable for 'machine name goes here':