[drostie]

The basic answer is that (1 year) / (1 day) = 365.242199... is a pure number with no units associated to it, so there exists no set of units which can eliminate it.

The question then is, should we synchronize on the year, or on the day? The advantage of using the year is that it's a more stable unit of time; the length of a day is actually incredibly noisy and days are slowly getting longer every century as the Sun's and Moon's tidal forces deform the Earth, turning rotational energy into heat.

Unfortunately, there are a bunch of disadvantages. There are a lot of calendars in effect today, and they don't always settle on the same definition of "year" -- for that matter, there are a lot of astronomical definitions of "year" -- since the Earth's axis doesn't point at the same stars eternally, do you mean orbiting the Sun once relative to the distant stars (ignoring the axis) or do you mean coming back to the same tilt relative to the Sun so we can start the seasons over again (including the axis)? Or do you just mean a full cycle of phases of the moon, as lunar calendars do it?

The best way that I can see is to settle approximately on a day with an atomic clock; and push the question of actually trying to keep dawn at the same time each day (correcting for the slowdown of the Earth) to the time zones, which already sometimes try that in the sense of Daylight Saving Time.