A deadline fixed in legislation — which usually means nobody can extend it.
A statutory deadline is one set by legislation rather than by an authority's practice or a contract. The distinction is about who can change it: a practice deadline can be relaxed by the body that set it, and a statutory one generally cannot without amending the statute.
This is why some deadlines survive events that would obviously justify moving them. An authority may sympathise and have no power to help.
It also explains the awkward cases where a deadline lands on a Sunday and stands. Where the statute names a date and provides no shift rule, there may simply be no mechanism to move it.
All statutory deadlines are deadlines. The label records that it was set in legislation and therefore is unlikely to be movable.
See also deadline · filing deadline · grace period · roll convention
We hold this as assurance on the deadline records whether we read the instrument itself. See what we hold.