Regulations may provide for treating a person for the purposes of this Chapter as incapable of work as the result of an accident or injury when he would not be so treated apart from the regulations, and may also make provision -
(a) as to the days which, in the case of a person who at any time is, or is to be treated as, incapable of work as the result of an accident or injury, are or are not to be treated for the purpose of occupational injuries benefit as days of incapacity for work, and
(b) as to the day which, in the case of night workers and other special cases, is to be treated for the purpose of occupational injuries benefit as the day of the accident.