The idea of changing time units is pretty cool. I had a friend at uni who broke every activity into 30 minute lots for example, gym was 3 units (1.5hr). It helped him schedule better.

I do think that in order to change significantly, a lot of the conventions change alongside as the old models are no longer well fit to society. It happens slowly though, people live to hold onto tradition, even if they are no longer relevant or perhaps, harmful.