Board Thread:Consensus Track/@comment-732150-20180717015350/@comment-1251315-20180721140126

I don't know how the region releases work, but I do know every DVD boxset I purchase includes Japanese and English audio on the same disk. Afaik, all DVD releases are done via a collaboration of various companies, but most include Viz Media, Manga Entertainment and Madman Entertainment (Viz being the licensor, Manga/Madman being the distributors for Australia and Europe). IIRC, Manga Entertainment did the vast majority of the publishing of the DVD's in the UK up until the war arc (around the time when Jinin Akebino was introduced), after which the licensing changed hands and were under Madman Entertainment.

If it can be supported, maybe have different parameters for each region it was released under for the DVD sets, if that data is available and can be reliably sourced. Unfortunately, the seasons listed are often grouped by each arc, so an arc of just 7 episodes just gets counted as its own season, so dates can be more iffy when it comes to using season release dates.

Snapper's idea is quite good and I think is a good compromise to cover all grounds. All of Naruto was on a network, and only the first 100 or so episodes of Shippuden were on a network, after that it was just online/DVD releases only (which I suspect was because of the extreme censoring needed by this point that there wasn't anything left to air lol).

The most likeliest place to find DVD release dates would probably be the various pages on Amazon itself, which should show when the item was actually released (although I realise this won't work for all of them)