Every employee is entitled to at least one (1) weekly REST day.

EVERY EMPLOYEE HAS A RIGHT TO WEEKLY REST DAY. It shall be the duty of every employer, whether operating for profit or not, to provide each of his employees a rest period of not less than twenty-four (24) consecutive hours after every six (6) consecutive normal work days.

The general rule is that it is the prerogative of the employer to schedule his employees' weekly work day. The exception is when employees have a religious ground to object.

The employer shall determine and schedule the weekly rest day of his employees subject to CBA and to such rules and regulations as the DOLE Secretary may provide. However, the employer shall respect the preference of employees as to their weekly rest day when such preference is based on religious grounds.
In other words, the employer’s right and prerogative is subject to the preference in the choice by the employee of his rest day based on religious grounds. Article 91, in fact, makes the employer duty-bound to respect such preference of the employee if based on religious grounds.

Where, however, the choice of the employees as to their rest day based on religious grounds will inevitably result in serious prejudice or obstruction to the operations of the undertaking and the employer cannot normally be expected to resort to other remedial measures, the employer may so schedule the weekly rest day of their choice for at least two (2) days in a month.