In these two questions in Space Exploration Stackexchange the origin and use of the word "sol" to describe a solar day on astronomical bodies besides the Earth are being discussed. Like so many things in space exploration, I'm wondering if this usage of the word "sol" as one solar day has precedence in SF writing.
For the purposes of my own curiousity I'd like to know about usage prior to the landing of the Spirit and Opportunity rovers (Jan 2004) for which broad coverage in popular news and the internet continued for years. However as @user14111 points out in a comment below, "sol" was already in documented use (in popular media) as the name of a Martian solar day in 1976 - in connection with (presumably) the Viking 1 lander. So from an etymological perspective this would be the more relevant date (unless/until we find an even earlier reference).
I'm also interested if other terms were used to describe a solar day (of any solar system body). I am not looking for a "word for day" in some alien language. I'm looking for something either used by the writer in narrative to the reader, or in dialogue where
English Earth language is being spoken.
edit: I've changed "English language" to "Earth language". Space exploration is not "in English" and the previous remote-controled rovers on the moon "spoke" Russian and Chinese. Also, as was pointed out here, the word "sol" isn't English at all - it's Latin!