Predominantly, Band Pencil is designed to be used in one time zone, but this does not mean you are unable to organise events in different zones. Events are stored in Band Pencil as floating times. This means when the event is stored, the time isn't fixed to any particular time zone. This means an event at 7pm could be 7pm in London, or in New York.
The calendar will always set the floating time to your browser's current time zone and offset using the time zone you set in your account. This means if you added an event for 7pm London (GMT) and you're in New York (EST) it will show the event in your calendar as 3pm (GMT-4). This only has a real impact if you're using the calendar with specific times as dates are not offset.
If you do schedule events in multiple different time zones we strongly suggest you make the event an all day event (don't set times) and set the actual times in the Event Timings Breakdown field with the time zone. This will help avoid confusion. It also avoid you having to mess on with setting the correct time zone offset for each event.
Don't let this worry you, we have loads of different users managing events across the world and it works perfectly fine for them! If you do have any further question please contact us.