Nope, 0-day means it was exploited in the wild before the company knew about it. Basically, the company had to rush to patch it because it was already being exploited. It means black-hat hackers found it and exploited it before the white/grey-hat hackers reported it. If white-hat hackers found it first, they’d have already alerted the company and given time to patch it before they announced the vulnerability. But since the black-hat hackers found it first, it was a 0-day.