Cs, why do you need to ask from dira batachtonim – ask better. If Hashem decided to create the world, it seems that there was a time that he did not, so how could he have changed his mind?
Rav saadya gaon dealt with the issue a thousand years ago in emunos vedeos, and he says that Hashem always wanted to create it. Some add that that our very concept of before and after had to be created too, along with time.
Same thing with dirah batachtonim.