Terrayn treats time differently than we do in the real world. For instance, 60 seconds in a minute... 60 minutes in an hour... 24 hours in a day?! Who came up with these numbers?
Instead, one day in Terrayn is equal to 5 hours in real life. Exactly. No more, no less. Why 5 hours? We want to be sure that every player has the chance to experience different times of the game. This really matters for players who play the same time every day for perhaps an hour or two. We're looking out for you!
So, this leaves us with 18,000 real life seconds to turn into one day. First, we decided to have 100 seconds in a minute. It's a nice round number and translates well. We then have 100 minutes in an hour. Again, a nice round number. Finally, there are 10 hours in a day. So, the time '9:99:99' is a completely valid time and is the last second in the game before ticking over to the new day. This means that 0.18 real life seconds is equal to 1.00 game seconds. Do the math and you should see that 1 day in Terrayn is equal to 5 hours in real life.