13.—(1) In this section "daily rest period" means a rest period referred to in section 11.

(2) Subject to subsection (3), an employee shall, in each period of 7 days, be granted a rest period of at least 24 consecutive hours; subject to subsections (4) and (6), the time at which that rest period commences shall be such that that period is immediately preceded by a daily rest period.

(3) An employer may, in lieu of granting to an employee in any period of 7 days the first-mentioned rest period in subsection (2), grant to him or her, in the next following period of 7 days, 2 rest periods each of which shall be a period of at least 24 consecutive hours and, subject to subsections (4) and (6)—

( a ) if the rest periods so granted are consecutive, the time at which the first of those periods commences shall be such that that period is immediately preceded by a daily rest period, and

( b ) if the rest periods so granted are not consecutive, the time at which each of those periods commences shall be such that each of them is immediately preceded by a daily rest period.

(4) If considerations of a technical nature or related to the conditions under which the work concerned is organised or otherwise of an objective nature would justify the making of such a decision, an employer may decide that the time at which a rest period granted by him or her under subsection (2) or (3) shall commence shall be such that the rest period is not immediately preceded by a daily rest period.

(5) Save as may be otherwise provided in the employee's contract of employment—

( a ) the rest period granted to an employee under subsection (2), or

( b ) one of the rest periods granted to an employee under subsection (3),

shall be a Sunday or, if the rest period is of more than 24 hours duration, shall include a Sunday.

(6) The requirement in subsection (2) or paragraph (a) or (b) of subsection (3) as to the time at which a rest period under this section shall commence shall not apply in any case where, by reason of a provision of this Act or an instrument or agreement under, or referred to in, this Act, the employee concerned is not entitled to a daily rest period in the circumstances concerned.