While I would definitely prefer your clock to what we have, I don't feel it adequately encapsulates the concept of a D&D adventuring day in a video game. I would argue that it would be harder to decide which amount of time represents a day, than deciding how much content one should cover in order for one day to have passed. Like, what is one in-game day? 2 real-time hours? 3? Half an hour? How does that translate to quests of various lengths?
I'm not sure it's harder to determine which amount of hours represent an in game day than deciding which amount of points represent every single events.
Time does not have to translate to quests or dialogs or anything else... Time is constant except maybe in turn base (should time pass in "in-game real time" while we're fighting ? Or should every turn represent "x" amount of in-games hours/minuites ? that's another thread).
A question about quests : nightsong in exemple.
How would we earn resting points ? For every step ? For specific step ? Only when you reach BG and give it back to the wizard ?
It's not that simple.
As I said I find the idea very interresting but to be honnest I can't think about good solutions to solve the issues raised in this thread (yet?).