There are so many factors that could determine how long Oddworld time is.
- The time it takes for Oddworld to rotate
- The time it takes for Oddworld to do an orbit of the solar systems
- The amount of day/night that exists in that particular area of Oddworld (Mudos)
- The length of time that Oddworldians use to measure time (i.e. how long their seconds, minutes, hours are)
- Possibility of Oddworld having two suns instead of one
Actually no one ever could know this... even OWI probably never really thought about this. Thus the reason we see "earth" time measurements in the games, because that is all we they have to go on.
You would think that generally a planet that is that large would have longer times than Earth, but taking in some of the other points of I have mentioned above, the conclusions to this are certainly many!
Abe Babe...