how do I retrieve a value after using setx?

Question

I need to store a value (a time stamp) and retrieve it later in batch files. So I have searched SO for answers on how to store a persistent variable and found setx.

Answer 1

from the doc (setx /? )

Because SETX writes variables to the master environment in the registry, edits will only take effect when a new command window is opened - they do not affect the current CMD or PowerShell session.