December 2019 was full of nostalgic posts remembering the best films, food, TV shows, and travel destinations of the decade. Even Twitter made a list of the decade’s best tweets – but plenty of Twitter users are here to remind you 2019 wasn’t, in fact, the final year of the decade.

And why is that?

Time experts (okay, that’s not what they’re called but it sounds cool) say that Anno Domini (A.D.) didn’t have a year 0. The A.D. system is the basis of how we keep track of time in our modern era.

As the argument goes, 1 was the first year in the Anno Domini system, so the first year of each decade is the one beginning in 1.

Of course, it makes sense that people would track the decade by the changing tens place. If you study the year 1960 in history class, books will say it’s a part of the 60s. The same would obviously be true about the 20s, if we were to think about it logically.

Except that it’s just not entirely logical.

Not everyone is happy about this, and some of those people have aired their grievances on Twitter.

But Twitter has been around for 10 years now and this argument has played out on the site before.

Some people (most people) don’t really care about these technicalities because frankly, it’s easier to go with the things the public recognizes even if it’s wrong.

Others tried to find a compromise.

Yes, arguing over the end of the decade seems like a waste of time, but it also shows us that time is subjective. It’s difficult to change someone else’s perspective on humanity’s milestones.

In the meantime we’d like to know your thoughts, did you celebrate 2019 as the end of the decade or are you trying to get people to understand that the decade hasn’t technically ended? We’d love to read comments about this!