change timezone

Hello

Can anyone inform me how to change the timezone of solaris 11 ?

I have read a lot of different suggestions on the internet, like :

- setting the init service but keeping the TZ to localtime

- each user should have his own timezone by setting it up in his environment

- modifying the /etc/init

And lots more.

What is the difference between using EET and other like UTC or GMT ?

What is the best configuration for our country (Cairo, Egypt) ?

And in case it is needed to update the java time too, what to do ?

Just need the experts opinion.