For each system variable ro re-set, you need add to .htaccess a code of line as follows:
php_value setting_name setting value
An example, setting date.timezone:
php_value date.timezone "Europe/Vienna"
- It may happen that sometimes this kind of operation is impossible: the server may be configured to make it uneffective (especially if you're using a shared hosting plan).
- Not every system variable may be override using .htaccess
So, to check if your correction is effective, run a phpinfo() to see if the value has been modified or not.