Has the year always been the same duration?

There are some writings that claim that the year was previously shorter than it is now. Some people have suggested the year has been 360 days long in the past. Velikovsky mentions a myth that says 5 days were taken from the moon and given to the sun. That is the previous lunar year was 12 × 30 (= 360) days and the old solar year was 360 days. The current lunar year is now 354 and a bit days, solar year 365 and a bit.

Some suggest that the year may have been even shorter prior to this.

If the year has been of different duration (measured in days) there are 2 options:
Scenario 1. The earth's spin was previously slower and has since speed up. Scenario 2. The earth's orbit was previously closer to the sun.

Of course it could be a combination of the 2.

Scenario 1
If the earth's spin was slightly slower and has speed up (presumably by a factor of ~365/360) then the absolute duration of the year is unchanged but more days pass in a year because the days are now shorter.

Scenario 2
If the day length is unchanged then a shorter year would be absolutely shorter, the duration of the year is related to the distance from the earth to the sun (and eccentricity of the orbit, though the earth's orbit is close to circular)

The month is currently 29.5 days long. Scenario 2 with an altered earth orbit would have a shorter year but the same duration of the month. Scenario 1 would have a longer old day of 24.35 hours (360/365.25×24) which would make the previous month seem shorter at 29 old days rather than the 29.5 days it currently is. Of course the orbit of the moon could have changed at the same time (or at another time). The asymmetrical cratering of the moon suggests catastrophe in the heavens.

An idea that came to me reading a footnote in the book In the Beginning: Compelling Evidence for Creation and the Flood by Walt Brown. I have not actually read the book so this may have been in the book, nevertheless I have not seen it previously: If the atmosphere pre-flood had a lot of water in it to precipitate (eg. vapour canopy theory), it would have some mass. After the flood the mass would now be at sea level, and by conservation of angular momentum, the earth would speed up, the amount depending on the height from which it precipitated. Consequently shortening the day and "lengthening" the year (in number of days).

It would be interesting to look into this in terms of the amount of water and the original height of the water. The mass may be completely insignificant and the change in spin speed inconsequential, but I haven't seen figures.

Of course any change in the earth's year may be unrelated to this and be all to do with the earth's interaction with the moon and other celestial phenomenon. Or the change in year length may have been at a different time than the flood: note Joshua's long day and Hezekiah's sundial. Or perhaps there was more than one episode.

Or course the duration of the day and the month may have been the same as the current figures since creation. It does make one wonder why the ancients had stories to the contrary though.