If you allow for fantastic fiction, units of money, and mortality rather than Earth nature, Charles Dickens's A Christmas Carol, published 19 December 1843 states that the Ghost of Christmas Past comments on Old Fezziwig:
"Why! Is it not? He has spent but a few pounds of your mortal money: three or four perhaps. Is that so much that he deserves this praise?"
For a more sci-fi perspective, and calling out Earth non-explicitly, Plan 9 From Outer Space (1959), Eros comments on Earth technology:
"Since the beginning of your time, we have been far beyond your planet. It has taken you centuries to even grasp what we developed eons of your years ago."
Less explicitly (and back to fantasy, or maybe eschatology), Isaac Asimov's The Last Trump, published June 1955, has Etherial ask about the scheduled date of the end of the world as follows in his (successful) argument that it's unenforceable due to how non-specific it is because of how many ways Earth does dates:
"The document, approved by the Council of Ascendants and signed by yourself, authorizes the Day of Resurrection at a specific time of a specific day of the year 1957 as Earthmen count time."