Key facts of the case - The plaintiff, member of the Adventist Church of the Last Day (Iglesia Adventista del ultimo día) and employed by “Industrial Dik Sociedad Anónima”, received a letter of dismissal after having left her post for unjustified reasons. Plaintiff alleged that due to her membership to the abovementioned Church, she could not work on Fridays from sunset onwards, which resulted in an incompatibility between her religious obligations and her labour obligations.
Action before the Constitutional Court is based on violation of the plaintiff’s religious freedom guaranteed under Article 16 of the Constitution, Article 3.1 of the Religious Freedom Act (Ley Orgánica de Libertad Religiosa) and Article 6 of the 106 ILO (which states that weekly days off shall coincide, whenever possible, with the day that has been set by the use or traditions of the region or country).

Main reasoning of the Court - The Court does not uphold the claim. The rights and articles invoked by plaintiff may not be used by one of the contracting parties to impose on the other any changes to the contract that it deems pertinent.
The minimal weekly rest established in Article 37.1 of the Spanish Labour Act (Estatuto de los Trabajadores or ET) may be changed by the mutual consent of the parties.
Furthermore, the Court indicates that Sunday weekly rest in Spain is a labour and secular institution established by tradition, which can nevertheless be modified through collective employment agreement, but not through an individual pact.