Paul Wheaton here said �The norm seems to be studying about 20 hours a week for a month.�
But of course, all people are different and preparations may be 2-3-4� times longer. I am also beginner in Java, although I have more than 10 years of programming experience, and it took me nearly 2 months to feel comfortable with exam questions (to score around 90% on mocks). I think most important thing is not to rush and not to compare you with others, who may seem study faster than you can. I did it and� nothing but frustration. BTW, on
Maha�s page you can find some useful tips for your preparation. Good luck!!!