What do you mean using a graphing tool??? Which tool??? In XL dates are
ultimately stored as plain numbers. For example todays date at 12:49 in the
afternoon is stored as 39699.5340861111
39,699 is the number of days since Jan 1 1900 (not entirely true but good
enough for this discussion)
..5340861111 is the time. We are just a little more than half way though the
day. If you get rid of the decimal then you are at midnight... You do not
indicate if your 12:00 is am or pm which would mean 0 or .5 was being passed
to the graphing tool...