How do you say 'zeroth' in spanish? As in primer hora, zero period?

Question

How do you say 'zeroth' in spanish? As in primer hora, zero period?

Answer 1

Ceroésimo

Answer 2

I couldn't tell you how to say zeroth in English, let alone Spanish.

primera hora

Answer 3

Well, zeroth (that's /zee'-roth/, Q) is a word in English. It's rare, but some series (especially in computer science) begin with 0th place instead of 1st. Also, in math involving powers, you can have some number X to the zeroth power (for example).

I've googled and found zilch. However, I did get the impression that Spanish allows the word cero to double for the the ordinal as well as the usual cardinal sense (i.e., zeroth and zero).

Hopefully, a native will weigh in with a definitive report.