Essential Services Act 1981

A person convicted of an offence against a provision of this Act in respect of a continuing act or omission—

is liable, in addition to the penalty otherwise applicable to the offence, to a penalty for each day during which the act or omission continued of not more than one-fifth of the maximum penalty prescribed for that offence; and

is, if the act or omission continues after the conviction, guilty of a further offence against the provision and liable, in addition to the penalty otherwise applicable to the further offence, to a penalty for each day during which the act or omission continued after the conviction of not more than one-fifth of the maximum penalty prescribed for the offence.

If an offence consists of an omission to do something that is required to be done, the omission will be taken to continue for as long as the thing required to be done remains undone after the end of the period for compliance with the requirement.