China DOS Union

When I was bored, I tested a short piece of code. Like this...

@echo off&setlocal enabledelayedexpansion

echo %time%

set time=a&echo !time!

pause

echo %time%

echo %time%

echo %time%

pause

Changing time to random gives the same result. Aren't system variables like these all dynamically calculated in real time~? Why is it that after assigning a value manually, it no longer changes in real time?

In the set /? help there is:

If the user explicitly defines a variable with one of these names, then
that definition will override the dynamic one described below:

If you've learned C, it should be fairly easy to understand. You can think of it as a local variable overriding a global variable.