We have to take the flag at 15:00 as bench mark..now two time-zone rows are formed..one after the benchmark (say A) and one before (say B)...now find out the differences in each flag's time zone... Once we get the hours for each flag, look at the computer showing the time..(which is 01:55 here), then start adding the result hours to the given time, for the flags in A and subtracting for the flags in B.