When applying the Empirical formula on a data set, for example calculating 1, 2 or 3 standard deviations below and above the mean of a data set, for some cases, this might not make sense. For example, when dealing with data of time, is it acceptable to say:
$mean - (2 * s.d.) = -5$ hours?
Or does this truncate to $0$ hours?
Thanks for any insight!