How do I determine when my Macbook pro was manufactured?
I'm always hesitant to recommend an app to do what a terminal command could do... but I cannot for the life of me find the terminal command to output the date of manufacture of any given Mac.

So...

I recommend the free app coconutBattery for this task.  It's a battery health monitor, and it happens to also show the date of manufacture of the Mac that it's running on.

Installation

brew cask install coconutbattery (if you use Homebrew) or download from the developer's site.