Help: Time Zone Offset Calculation

I've got a CSV file that has been sent to me where each entry has a vehicle reports in with certain metrics. Included in these metrics are the time the metric is reported. The problem I am having is that the time is delivered in UTC date/time (in Column A). Column B has an "offset" to show how many hours difference there are between the UTC time and the local time for that particular vehicle. I am trying to figure out a calculation, but am having trouble. Here's the problems I am having:

Problem 1 - My initial thought was to use "Text to Columns" with space as the delimiter, thinking I could just run a simple subtraction formula once completed. The problem here is that if an entry is recorded after 7pm local time, the UTC time moves into the next day, and the simple subtraction formula will not take that into account.

Problem 2 - Even if there was a workaround, it seems that the numbers in the "Offset" column don't work well with time calculations because they are not a time (it's -5, -6, -7, or -8).

I've uploaded the CSV here, and would appreciate any help...thanks in advance!

excelforums.csv

I think I may have just answered my own question.

Step 1 - Run a Text To Column conversion on the offset column to strip out the - sign.
Step 2 - Change properties of values in Column C to "Number"
Step 3 - In Column D, run the following formula: A2-TIME(C2,0,0)

Autofill to end - we're done. Is this correct?

Oh, DOH, that makes even more sense. I guess it doesn't matter as long as the results are the same, correct?

Is there a preferred convention for doing something like that?

I am still assuming that steps 1 and 2 are needed before the COLX - TIME(COLY,0,0) or the COLX-COLY/24 could be done, right?