Most things in mojoPortal do store the dates as UTC and adapts it to the user profile time zone. However the free Event Calendar in mojoPortal is one of the older features and it does not do this.
In many scenarios for Events it is more desirable to publish events according to a specific time zone such as the actual time zone of the location where the event is. Event Calendar Pro allows you to choose a specific time zone for the events or to have it adapt to the user time zone. It can also display the time zone so there is no ambiguity.
Sales of Event Calendar Pro help support the ongoing development of mojoPortal. For that reason I have no intentions of making improvements other than bug fixes to the free Event Calendar included in mojoPortal because that would work against sales of Event Calendar Pro. People can clone the free Event Calendar and modify it to their needs or they can consider helping the project by purchasing Event Calendar Pro.
So I'm sorry but I'm not going to consider this a bug but a feature request and I have no current intentions of implementing this feature improvement for the free Event Calendar. People can edit the free event calendar by setting their own time zone to the same as the site default and then events will always show in the time zone of the site. To keep it from being ambiguous you could add html to the page to indicate the time zone.
Best,
Joe