Variable Placement

[eluser]CI_Newb[/eluser]
I've read arguments from both sides, but where do you keep your variables for your application?

1) All variables stored in a central file
2) Variables are created on the fly in the model/view/controller when needed.

I'm talking common variables. Example

Code:

$cur_date = date ('Y-m-d');
$cur_time = date ("U");
$month_num = date ('m');
$year_month = date ('Y-m');
$cur_month_name = date ('F');
$cur_year = date ('Y');
$date_yesterday = date ("jS", time() - 86400);