Sources of Law and Temporal Validity

The Life Cycle of a Norm

A law is not born the day politicians shake hands. It follows a strict life cycle, and each stage has legal consequences.

1. Enactment: Parliament passes the text; the head of state sanctions and promulgates it.

2. Publication: the norm appears in the Official Gazette (BOE). Unpublished law binds no one — publication is what makes ignorantia iuris non excusat (ignorance of the law excuses no one) a fair rule rather than a trap.

3. Entry into force: the norm starts applying. By default, after a vacatio legis of 20 days from publication — a grace period for everyone to adapt — unless the norm itself sets another date (immediately, or months later for complex regimes).

Timeline: publication → vacatio legis (20 days by default) → entry into force.

4. Repeal: norms die by express repeal (the new law lists what it kills) or tacit repeal (incompatibility — the new rule contradicts the old, and being of equal or higher rank, displaces it). Laws do not lapse from disuse.

Non-retroactivity. By default, norms govern the future: situations arising after entry into force. The Constitution guarantees non-retroactivity for punitive and restrictive norms — no one can be sanctioned under a rule that didn't exist when they acted. Exceptions run the other way: favorable retroactivity (a lighter penalty reaches back) is allowed.

For business planning: a contract is judged by the law in force when it was concluded; a tax by the law of its accrual period. Reading a norm's transitional provisions — which situations follow the old rule, which the new — is where lawyers earn their fees.

Each stage, one consequence

Common pitfall: Assuming every law waits 20 days. The vacatio legis of 20 days is only the default — the norm itself can enter into force the day after publication or a year later. Always check the final provisions first.