Section 804-A. Good behavior allowances for certain civil commitments

1.
  Every person confined in an institution serving a civil commitment for a
  fixed period of time, whose release is  not  conditional  upon  any  act
  within   his   power   to   perform,  may  receive  time  allowances  as
  discretionary reductions of the term of his commitment not to exceed, in
  the aggregate, one-third of  the  term  imposed  by  the  court.    Such
  allowances  may  be  granted for good behavior and efficient and willing
  performance of  duties  assigned  or  progress  and  achievement  in  an
  assigned  treatment program, and may be withheld, forfeited or cancelled
  in whole or in part for bad behavior, violation of  institutional  rules
  or failure to perform properly in the duties or program assigned.
    2.  Allowances  based  upon  commitments of less than one month may be
  granted, and in such case the maximum allowances shall be  one  day  for
  every three days of the commitment. In no case, however, shall the total
  of  all  allowances  granted  to any such person exceed one-third of the
  time he would be required to serve,  computed  without  regard  to  this
  section.
    3.  No person shall have the right to demand or require the allowances
  authorized by this section. The decision of the sheriff, superintendent,
  warden or other person in charge  of  the  institution,  or  where  such
  institution is under the jurisdiction of a county or city department the
  decision   of   the  head  of  such  department,  as  to  the  granting,
  withholding, forfeiture, cancellation, or restoration of such allowances
  shall be final and shall not be reviewable if made  in  accordance  with
  law.
    4.  The state commission of correction shall promulgate record keeping
  rules  and  regulations  for  the  granting,  withholding,   forfeiture,
  cancellation and restoration of allowances authorized by this section.
    5.   Upon  commencement  of  any  civil  commitment  as  described  in
  subdivision one of this section, the provisions of this section shall be
  furnished to the person serving the commitment and the meaning  of  same
  shall  be  fully  explained  to  him  by  an  officer  designated in the
  regulation to perform such duty.