The period of indeterminacy associated with an indeterminate event is
an anchored duration that delimits the range of possible times during
which the event occurred. The event happened sometime during the
period of indeterminacy but it is unknown exactly when. An anchored
duration is usually referred to as an interval, however, in this
context, we prefer to call it a period because the syntactic
difference between an ``indeterminate interval'' and an ``interval of
indeterminacy'' is slight, while the semantic difference is great.
Hence, while using ``interval of indeterminacy'' might be more precise
(+E9), it would also be more confusing (-E8). Using ``fuzzy
interval'' would also be confusing due to the influence of fuzzy
databases (+E5).