There can't be any exact dates for when it's safe because that depends on the (highly variable) water level in the river, which depends on rainfalls.
Getting there requires taking a boat, a short rocky hike and swimming through a safe part of the river before you get to the pool itself (source: a TV show I saw). You should only do it as a guided tour, in ...
The reason the dates vary is because high water season varies. Guides won't take people when the water levels are too high, because they have to take it too.
There's a really good blog post on this which details:
the steps involved getting there (boat ride, pics of the rocky walk, and the jump you need to do to get in
tips on how to manage it (any girls ...
Most other forums online indicate that now the Zimbabwean ATMs in Vic Falls dispense USD.
VictoriaFalls-Guide.net indicates that:
Barclays Bank and several of the other banks now have ATM cash
withdrawal facilities accepting Visa and Master Cards and dispensing
US$ cash. The limit is the same as your limit back home. Charges are
$1.25 per ...
There is also an ATM I can't remember the brand in the shopping area near chicken-inn off the main road.
The Barclays ATM was giving out large notes (100USD) which can be hard to get rid of in the local shops. Its probably best to have a bunch of 1, 5, 10 USD notes with you when you arrive.