What time zone does it begin in, im in australia so have been waiting all day.

7am eastern time

I'm in Melbourne, started at 8pm last night on xbox, so if it's 24 hours later for the other platforms then it should have just opened.

If it's an international release time then in about 3 hours.

12:00 UTC/GMT

I've just come here to check what time it starts, and I wasn't disappointed.

Shame it's not started already though.

@egan85: I'm also in Melbourne, and the PC Open Beta has yet to begin, though I played some of the Xbox beta earlier than this last night, so I don't know what's going on

Its the usual case of playing on PC and having the betas starting earlier on consoles because of agreements between publishers and console platform owners (Sony, Microsoft).

This is also the reason why Far Cry :primal releases on consoles on 23th and on PC on march 1st.