It looks like MLK is onto something here.

The Basic Conditions of Employment section 37 is as follows:
1) Subject to section 38, a contract of employment terminable at the instance of a party to the contract may be terminated only on notice of not less than--

a) one week, if the employee has been employed for six months or less;

b) two weeks, if the employee has been employed for more than six months but not more than one year;

c) four weeks, if the employee--

i) has been employed for one year or more; or

ii) is a farm worker or domestic worker who has been employed for more than six months.



2)

a) A collective agreement may permit a notice period shorter than that required by subsection (1).

b) Despite paragraph (a), a collective agreement may permit the notice period of four weeks required by subsection (1)(c)(i) to be reduced to not less than two weeks.
I couldn't track down a copy of Schedule 8, though.