That's still time travelling. Not sure if going by hours would affect flowers though, but it definitely has the Turnip and Tom Nook side effects.
Um, the ones that are wilting... are you sure you watered them? It's just that the flowers don't sparkle in Wild World so it can be a bit tricky to tell where the watering can actually watered.
Alright, I don't actually know what I'm on about. Worth a stab, eh?