The lifetime of a site is defined via the Delete Site After option within the Easy Plugin Demo settings page. When a site is created, that lifetime is added to the current time to generate the time at which the site will expire.
Following expiry, the site will soon after be deleted, together with all its content, and if they have no access to other sites, any associated users too.
Without the Premium Pack extension installed, there is no interface to change the expiry date for an individual site after it has been created. However, if the Premium Pack extension is installed, a Super User can edit individual sites via the Network Admin -> Sites screen. When the edit link is clicked, the EPD Demo Settings tab can be accessed.
Clicking the EPD Demo Settings tab, reveals the page whereby the expiry date can be adjusted. The current expiry date and time is displayed in the input field. You can adjust this value as needed and click the Edit Demo Site button to save your changes. A confirmation page will then be displayed.
If you enter the expiry date in the wrong format, the expiry date will remain unchanged. The format to use in accordance with the PHP date formats is Y-m-d H:i:s. For example 2020-11-08 08:30:00.
Alternatively, if you do not want the site to ever expire, you should enter 0 into the input field and click Edit Demo Site.
Note that if the site you are editing is the primary site, defined as a clone master, or is defined within a demo template to be cloned from, you will not be able to set an expiry date. These sites are auto set to never expire.