I mean, I think two sets of 12 hours dates back to Ancient Egypt, basically as old as the Pyramids, so quite a bit older than the Bible itself. But note that most of those cultures used equal divisions per day, expanding or shrinking the length of an hour depending on the season, e.g. Egyptian water clocks would have different gauges for each month. So they would hold dawn or dusk constant and expand or shrink the sizes of hours rather than our system of holding hours constant and letting dawn and dusk move around. Constant hours are a much more recent invention, generally speaking for most people (people who worked with the stars excepted) starting up around the time of railways, when it first started to matter what time was for an area larger than the hearing radius of a clock bell tower. (I don't care what time your town has versus my town, so who cares that your 5th hour of the night is more like my 4 hours and 45 minutes of the night? Until we need to run a train all the way through both of our towns and now we need to synchronize!)