Strictly for iPad, ZonedOut HD helps you see what local time is anywhere on earth, schedule meetings, share by email or text, and manage your calendars. The best time zone app for the iPad. Bookmark groups of timezones for easy reference.
Has more than 600 built-in time zones, including the UNIX zones, all North American zones, hundreds of airports worldwide and the 25 NATO / ICAO aviation time zones.
Uses Internet search to figure out the time zone of anything that MapKit can find, and you can assign names to timezones as you prefer.
Original ZonedOut app was New & Noteworthy for the iPhone in the Business category January 2011.
Try ZonedOut Lite (ad-supported) on the iPhone for free.