Just giving a heads up to anyone who uses the divide by 86400 method of working out dates.
Just looking through a system i have inherited and found that any date range including 28/03/2005 gives a value one less then it should when the @integer command is used.
This is due to the change in british summer time, making notes think the 28th only had 23 hours meaning 24th to 28th gives 3.95833333333333. I fixed this by using @round.