Portunes

In ancient Roman religion, Portunes (alternatively spelled Portumnes or Portunus) was a god of keys, doors and livestock. He protected the warehouses where grain was stored. Probably because of folk associations between porta "gate, door" and portus "harbor", the "gateway" to the sea, Portunus later became conflated with Palaemon and evolved into a god primarily of ports and harbors. In the Latin adjective importunus his name was applied to untimely waves and weather and contrary winds, and the Latin echoes in English opportune and its old-fashioned antonym importune, meaning "well timed' and "badly timed". Hence Portunus is behind both an opportunity and importunate or badly timed solicitations (OED).

His festival, celebrated on August 17, the seventeenth day before the Kalends of September, was the Portumnalia, a minor occasion in the Roman year. On this day, keys were thrown into a fire for good luck in a very solemn and lugubrious manner. His attribute was a key and his main temple in the city of Rome, the Temple of Portunus, was to be found in the Forum Boarium.