name 'times' is used prior to global declaration - But IT IS declared!

From the Python documentation:

Names listed in a global statement must not be used in the same code block textually preceding that global statement.

https://docs.python.org/reference/simple_stmts.html#global

So moving global times to the top of the function should fix it.

But, you should try not to use global in this situation. Consider using a class.

From the Python Docs

Names listed in a global statement must not be used in the same code block textually preceding that global statement.

The global declaration is when you declare that times is global

def timeit():
    global times # <- global declaration
    # ...

If a variable is declared global, it can't be used before the declaration.

In this case, I don't think you need the declaration at all, because you're not assigning to times, just modifying it.