Anyway, I was so pleased with this compliment that I fleshed out the idea, and I present to you, daylight-based time:

Every day has 12 hours of daylight and 12 hours of night; hours are simply very flexible concepts. (Yes, this means in the winter, at certain latitudes, you have only 12 hours in the day. Sorry.)

Minutes and seconds are also defined relative to the hour, so they are longer in the summer (daytime) than the winter (daytime) and vice versa at night. It was important to maintain continuous differentiability, however, so they change smoothly over the course of the day, month, and year. Except at dawn and dusk, obviously.

This flexibility has some downsides, and so there is also defined a Standard International Hour (and Minute and Second), defined as the first hour (, minute, second) of January 1st, 1936, at the peak of Mt Fuji. (Note that the first second and minute of the Standard International Hour are the same as the Standard International Second and Minute, respectively, but these are not the same as the average second or minute in the Standard International Hour, so it's important to define which one you're using.)

Be assured, however, these only change when there are advances in astronomical accuracy or precision that adjust our understanding of that span of time in 1936. Or changes to geographical accuracy and precision that affect the position of the peak of Mt Fuji, I guess. Thus we preserve the Classical Standard International Hour (, Minute, Second) and update only the Updated Standard International Hour (, Minute, Second).

Strangely, sundials are less useful than you'd think, and an accurate mechanical watch has yet to be built.