I released Time Difference Calculator app "TDCalc".

World clock tells you "What time is it now in US or UK". But does not tell you "What time will be in US corresponding to tomorrow 8:00 in Japan?".

This application tells you any time in any place as you choose.

TDCalc for iPhone 3GS, iPhone 4, iPhone 4S, iPod touch (3rd generation), iPod touch (4th generation) and iPad on the iTunes App Store

• Automatically detects your timezone.
• Support daylight saving time(1 hour).