That reminds me a constructed world that I'm building, roughly based on Earth after a few millions of years. It uses decimal time - the day is split into eight, then 100, then 100 again.
It's a poor system though; getting whole amounts from dividing by 3 is far more valuable than doing it for 5. If anything, it makes me wonder if we shouldn't be shifting our number system to base-12 instead of base-10.
Why split the day into 8?
You definitely have a point with base-12 though. If base-10 wasn't so ingrained already, base-12 would be a very logical choice. You can even count to 12 easily on one hand, using your thumb to keep track of where you are and counting on the segments of each of your 4 other fingers.
Why split the day into 8?
Because the in-world people who devised this system measured Earth's day as around 80ks (it's actually 86.4ks). And splitting 80ks by eight gives you neat 10ks "slices", as if forcing it into a decimal system.
Relevant detail: the people who did this were colonists exploring what they believed to be an "unknown planet", without realising that it was humankind's birthplace. Most info about Earth has been already lost back then, including our origins.
You can even count to 12 easily on one hand, using your thumb to keep track of where you are and counting on the segments of each of your 4 other fingers.
Sometimes I do this. It could be used to count to 144 using both hands (use one of the hands for the twelves and another for the units), although 60 is more practical.
