Custom timezone selection example

Pressure radio are using the ability to pass a timezone code to the plugin to display events in the user’s chosen timezone.  They offer a few preset links, as well as  a complete dropdown list.

If you want to do something similar, simply add the necessary html before the shortcode.

WordPress itself has the html required for the timezone list in the Settings> General tab, or some form generators will do it for you.

Calendar events list with timezones