Summer Working Hours and Acquired Rights: Supreme Court Ruling Clarifies the Conditions

Is the Summer Working Schedule an Acquired Labor Right?

With the arrival of summer, many companies and public administrations adopt intensive working hours to promote work-life balance and improve employee well-being. However, can employees claim this schedule as an acquired right if it has been applied for years?

In a Supreme Court ruling issued in May 2025, a collective dispute between several unions (CCOO, CIG, UGT, and CSIF) and the public entity Portos de Galicia has clarified when a summer working schedule can be considered a more favorable condition protected under Spanish labor law.

What Was the Dispute About?

For several years, part of the staff at Portos de Galicia had been enjoying a summer intensive schedule. However, in 2022, the entity excluded workers assigned to shift-based or special timetables, particularly the group of dock guards (celadores-guardamuelles).

The unions challenged this decision, arguing that it constituted a substantial modification of working conditions contrary to Article 41 of the Workers’ Statute, as it eliminated a long-standing practice they considered a beneficial condition.

What Did the Courts Decide?

Both the High Court of Justice of Galicia and the Supreme Court dismissed the claim, ruling that:

• There was no evidence of a constant, uniform, and generalized practice of applying the summer schedule to the affected group.
• The annual circulars issued by Portos de Galicia regarding summer working hours varied from year to year, and in several instances stated that the schedule was “pending determination,” ruling out automatic consolidation of the right.
• The 2013 internal directive of the Galician Government (Xunta de Galicia) regulating summer hours explicitly excluded personnel working shifts or special schedules, such as dock guards.
• There was no contractual clause, law, or collective agreement recognizing the summer schedule as mandatory or acquired.

Therefore, the Supreme Court concluded that Portos de Galicia’s decision did not infringe acquired rights and did not constitute a substantial modification requiring prior consultation or organizational justification.

What Does This Ruling Mean?

This case clarifies a key principle in labor law: not every repeated practice automatically becomes an acquired right.

For a summer intensive schedule to be considered an acquired labor right, several conditions must be met:

• Uniform application to the entire workforce or a specific group.
• Continuous and uninterrupted implementation over time.
• Voluntary and consistent application by the employer.
• Absence of annual limitations or conditional approval.

If these criteria are not met, the employer may modify or revoke the measure without it being considered a substantial change in working conditions.

How Should Companies Respond?

This ruling reinforces the importance of:

• Formally defining and documenting the conditions applied each year regarding working hours or seasonal flexibility.
• Avoiding repeated practices that might create expectations of permanence if not intended to become consolidated.
• Keeping internal records of organizational decisions and their justifications.
• Seeking legal advice to determine whether a modification requires the procedure under Article 41 of the Workers’ Statute.

The summer working schedule can be a valuable tool for work-life balance, but it will not always be a vested or acquired right. Everything depends on how consistently and formally it has been applied and recorded over time. This Supreme Court ruling provides greater legal certainty for organizations and helps them manage seasonal working conditions more clearly and confidently.