How do I get all files (w/o labels) before a certain date

I'm on a project (new to me, old to the company), but what they have in QA does not match Prod and is broken in QA.  They are using Azure.  How do I get the code as of that date of that PROD release to create a branch from there.  There's over 1300 files in this proj.

ty,

-Steve