From what i've heard from mates that have passed out - it's generally 2 weeks.
This will surely depend on when your phase 2 trade course starts, could be less than 2 could be slightly more , but it's the general rule of thumb.
Depends when your phase 2 course starts, I got a week, some people get two weeks then spend a little while in holding at their phase 2 establishment. The AAC blokes I passed out with had to be at Middle Wallop on the Monday after passout!
Little word of advice, I wouldnt bug your phase 1 DS this!