opportune
adj.happening at a very good or useful time. You use this to describe something that helps you achieve a goal because it comes at the right moment.
adj.occurring at a particularly suitable or advantageous time. Often used to describe an event that provides a useful opportunity for a specific action or decision.
“The rain stopped at an opportune moment for the picnic.”
“The company's stock price dropped at an opportune time, allowing the investor to purchase shares at a significant discount.”
“The sudden resignation of the CEO provided an opportune opening for the board to implement the structural reforms they had been debating for months.”
From Old French opportun, from Latin opportunus.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.