Well, we have several issues.
First, I don't understand the fixation on conditional formatting. Formatting
will only change the display of a cell. It won't change the underlying
number. I don't know of any way to use formatting to change a cell from 0840
(Eastern Time, say) to 1340 (Zulu time). So I'd give up on conditional
formatting if I were you.
Next you need to decide whether you want to permanently change the times to
Zulu times, or show Zulu time in a separate column. Most people would add
columns to their spreadsheet to show Zulu time. It's much easier to fix any
errors which occur, and it's easy to see the time difference. If you want to
permanently change the value, it's actually easier to do, but makes fixing
errors much more difficult.
Third, we need to know whether you have a number or and Excel time in your
cell. Most times have a colon in the display, yours doesn't. It will make a
difference in the solution.
Post back with answers to these questions:
1. Do you want to permanently change the values in columns F and G, or not?
2. What is the format you are using? Is it hhmm, or something else?
3. Where do you plan on storing the time difference between the time zone
used in the spreadsheet and Zulu time. In a cell (like B1)? Does it need to
be entered? Do you want to look it up somewhere?
What you want to do can be done, but I think it's going to take more effort
than you expected.
Regards,
Fred.