From checking the trademark database they registered their trademark only a few months ago (Dec. 21, 2023).

The first commit to AthenaDB was on Dec 11, 2023.

Is the prior use to a trademark the important date or the actual date of registration?

Unregistered trademarks are a thing too. In both cases its use in market time, not registration time.

Just because you could potentially win in court doesn’t mean you want to go toe to toe with Amazon legal, ya know?

The page says they hold the trademark to “Amazon Athena”. Does this come into conflict with a project named “AthenaDB”?

Even if you avoid legal issues, there's still the practical issues.

Fighting for ranking on Google. Conflicting tags on stackoverflow. Confused users sending you complaints about someone else's product. And so on.

Naming is hard. AthenaDB was the initial name of the MVP, I just never came up with a better one. Guess I'll have to do that now that I know AWS has another DB adjacent product with that name.

For me in Google at least the greek goddess wins, 50/50 shared with the movie.

Yeah, came here to say this, you’ll probably have problems with Amazon’s trademarked Athena database offering.

Indubitably, there might (p > 0.85) be an issue with the managed Presto database offered by Amazon, which is also named Athena btw.