Once you have logged into your Plesk Control Panel, you will select the "Website & Domains" tab at the top.


Now at the bottom of the page, click onto your website name to configure it.  Now you can click onto PHP settings as shown below to configure your desired PHP properties.



There are pre-defined properties, but you can specify ones not listed by scrolling to the "Additional Directives" section at the bottom of the page.



Here are some common additional directives:

• date.timezone=America/Vancouver
• open_basedir={DOCROOT}/;{WEBSPACEROOT}/;/tmp/