Calculate time in all countries for fixed time in one of them

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.

I did it already for the +gmt timezones and yes I have times for cities in big countries too; it was not my question.

How can I find out what time zone is in country with -11gmt when in country with +8gmt is 11am? Someone know?

E.g. I work with dates like this in Excel. I set type of cell data to date and put

1/1/11 4:30 (+4:30 gmt)

1/1/11 1:00 (+1:00 gmt)

Now I have a date e.g. 1/20/11 11:00 (11 am on imaginary date); all I need to do is

"1/20/11 11:00 AM" - "1/1/11 4:30 AM" = "1/19/00 10:00 AM" a开发者_如何学运维t (0 gmt)

10am I don't really care about date in this case just time. I cannot think right now how I gound precise time but it seems somehow work without even putting +8 gmt in there...

Anyway solution should look something like that.

What about countries that have more than one time zone?

11am in the USA....where? West coast (PST) or east coast (EST)?

How do you take into consideration daylight savings time?

There are a lot of things to consider to do time conversions correctly.

I personally wouldn't keep a table with country and hour conversions, but two tables. One with timezones and hours from GMT time. And then another one with city names and timezone mappings. This way instead of converting from USA to Russia, you would be converting from New York to Moscow.

I did do a quick search on timezones in excel, and I found this article. I hope that it helps.