No, the first century began Jan 1, 0000. Whether that year actually existed or not is irrelevant - we shouldn't change our counting system in the years 100, 200 etc.
It means just what it says. In the common calendar, the year after 1 BC (or BCE in the new notation) was 1 AD (or CE in the new notation). There was no "January 1, 0000".
No, it isn't, since you explicitly said to start the first century on the date that doesn't exist. What does that even mean?
The point is that some days got skipped over the centuries, but there's no need to make the Centuries have weird boundaries.
That's not what the poster I originally responded to is saying. He's saying the 1st Century should start on a nonexistent day.
That allows for consistent zero-indexed centuries. It doesn't have any other practical consequences that matter.
10 C = 50 F = 283.15 K
1 = 0.999…
Things can have more than one name. The existence of the year 0 CE is not in question. What’s in question is whether that’s a good name for it or not.
It's ultimately up to us to decide how to project our relatively young calendar system way back into the past before it was invented. Year zero makes everything nice. Be like astronomers and be like ISO. Choose year zero.
Or, just to add more fuel to the fire, we could use the Holocene/Human year numbering system to have a year zero and avoid any ambiguity between Gregorian and ISO dates.
Moreover, I definitely find the ordinality of pedantry more interesting than the pedantry of ordinality.
First, let's get rid of miles and feet, then we could even discuss this.
They might or might not have a point, but they already addressed yours.