As far as I know, Dithane was withdrawn from sale some years ago, and its now illegal to use it, but I could be wrong,maybe they've reformulated and that's what you've got.

Information re spraying for fungal prevention in the link below,, but it basically says in spring and again in June, unless the instructions on the product you have say something different

http://gardenerstips.co.uk/blog/flowers/vegetables-herbs/spring-spraying-fruit-trees-against-pest-and-disease/