Ah, I read a year was 365.25 days, not 365.2425 days, and because of that, I figured every 4 years is a leap year because of that. If you're right about the number of days, then yes, you would be correct about the leap century thing.
EDIT: According to Google, one year is 365.242199 days. That's... very precise. Just thought it would be worth mentioning.