This section applies where—
under the contract of employment under which a shop worker or betting worker who satisfies section 36(2)(a) was employed on the day before the relevant commencement date, the employer is, or may be, required to provide him with shop work, or betting work, for a specified number of hours each week,
under the contract the shop worker or betting worker was, or might have been, required to work on Sunday before that date, and
the shop worker has done shop work, or the betting worker betting work, on Sunday in that employment (whether or not before that day) but has, on or after that date, ceased to do so.
So long as the shop worker remains a protected shop worker, or the betting worker remains a protected betting worker, the contract shall not be regarded as requiring the employer to provide him with shop work, or betting work, on weekdays in excess of the hours normally worked by the shop worker or betting worker on weekdays before he ceased to do shop work, or betting work, on Sunday.
For the purposes of section 36(2)(b), the appropriate date in relation to this section is any time in relation to which the contract is to be enforced.