I have table with all countries GMT/UTC timezones, I need to see what time is in the rest of the countries when in USA is 11am-3pm Not on particular date just know the difference in time. I did my calculation like that I -5 GMT in USA and time is 11am then in Russia for example is +4 GMT. 5+4+11=20pm in Russia when USA is 11am, this works with countries that have + GMT zone but ones that have minus it shows wrong time. I am working in Excel please help me with advice on how to do it.