Today I watched a circa 2010 Dateline NBC episode and found that it is not listed in the Dateline NBC episode listing. I also see that the early years of Dateline NBC episodes are a mess! If I was able to determine the actual original airdates/title/episode of the early years, would i be allowed to fix them? would i need to get approval from TVMaze to re-number/re-date episodes?
I haven't gone that far back as I'm on my phone right now, but I'd suggest looking at NBC's Dateline Episode Guide.
If it's not listed on there, it will probably be hard to verify when it actually aired.
If you're going to be making a lot of changes, I'd suggest posting any sources first, so that we can verify it prior to any more time being spent on it.
The early seasons do look bad here, but that may just be because older information is hard to find/verify.
