Answer
An ejectment case must be filed within one year, but the reckoning depends on the type. For forcible entry, the one-year period runs from the date of actual entry or dispossession; when entry is made through stealth, it runs from the date the plaintiff discovered it. For unlawful detainer, the one-year period runs from the date of the last demand to vacate — where several demands are made, from the final demand.
The one-year period is jurisdictional for a summary ejectment case. Once it lapses, the owner can no longer file forcible entry or unlawful detainer and must instead bring an accion publiciana for the better right of possession, or an accion reivindicatoria to recover ownership, in the court of proper jurisdiction.