Good Afternoon, I’ve spent my last two weekends on this issue myself (my app needs to upload .csv files with hundreds of rows in each file).
As a precursor, i’m not familiar with Javascript, so i’ve been just trying a bunch of semi-random code snippets in the ServerScript action form the toolBox plugin,
using examples such as: Parse a text to a date - #2 by pork1977gm (tried idk how many different iterations of that implementation) which, after reading up a bit online and thru google should work,
but ultimately it was this post that helped me get my first successful text-to-date conversion: Toolbox plugin help - server script - #4 by paul29
(the link to that app’s editor showed me how to properly use the “data” field in that plugin’s configuration)
so here’s what i tried first (just to see if it manged to return the text in that dynamic field):
And sure enough, that’s all i apparently need? I hope there’s no kind of error this causes, and i’ll be doing some more testing, but jeez that was simple AF 
For Reference, here’s my OG .csv file :
And here’s what i get in my Database (date datatype):
