I would like to enter phone # in cell f, then in cell I, have it say
state,and in cell J,give time zone difference

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US/Canada? If so, phone numbers include area codes? If so, then you'd need a
table with area codes in the first (left) column, standard time (best to use the
time of day when it's midnight in London, UK, which is UTC/GMT), and daylight
savings time (on same basis as standard time - there are annoyingly many parts
of the US that don't observe daylight savings). Then, with your phone number or
area code stored somewhere named OAC (change as desired), use the area code from
the entered number as lookup value into the list of area codes (so use VLOOKUP),
and pull its standard time or daylight savings time. Do the same with OAC. Take
the difference between these two times - that's the time differential.