The Welsh Ministers may by regulations—
(a) amend section 225(4) by substituting a different period of time for the period for the time being referred to;
(b) amend section 226(1) by substituting a different period of time for the period for the time being referred to;
(c) amend section 227(10) by substituting a different period of time for the period for the time being referred to;
(d) amend section 228(2) by substituting a different period of time for the period for the time being referred to.