i phone 4S Time zone inconsistent in calendar view, event view and edit event view.

I travel very often and frequently change time zone on calendar events.

When I go to new time zone, I change it in settings. Some events change the time and others do not.

Even if I correct the time zone in edit for event, the time on the calendar page can be incorrect.

Example: Recently I was in Boston. Now I am home in Oakland CA. Going to Oakland A's game on Weds July 3 at 4pm.

In month calendar, under July 3, it says starting time is 7pm. Also in Even Details it says 7pm for start. Under Edit the event starts at 4pm and the time zone says Oakland ( This one is correct)

How can I correct this if it is correct in edit but not on calendar page?

I need these times to be correct as I depend on my alarms to keep me on time.

I appreciate any help I can get with this.