I definitely think the naming is more symbolism and cultural flavor. Like you mentioned, Zurvan means time in another language. Time, at least in Chrono Trigger, ebbs and flows, it changes and is changed; which is ultimately quite similar to water, an ocean. This theme of water and time flowing is used regularly throughout Chrono Cross - water itself is such a huge thematic element in the game.
I don't think it was necessarily a real place, although I do think that the term refers to the hidden sea that Chronopolis inhabits. That is where humanity in El Nido began (transported there in Time Crash eons ago) and probably, over time, became a myth akin to life and rebirth.
The sea gives life in El Nido (in the form of sustenance, travel, etc) and takes it away, too (loss of life, a la Miguel and Wazuki's fateful trip).
I do think this is an interesting question!