retrieve, or set, information whether time reflects instance (FALSE) or intervals (TRUE)
timeIsInterval(x, ...)
timeIsInterval(x) <- valuelogical; this function sets or retrieves the
attribute timeIsInterval of x, UNLESS x
is of class ST, in which case it sets or retrieves
this attribute for the time slot of the object, i.e.
timeIsInterval(x@time) <- value
object, of any class
ignored
logical; sets the timeIsInterval value
over, timeIsInterval