I've been thinking about alternative calendars recently. This is quite interesting. I wonder if we will ever get to a point that we can have a "base 10" calendar (10 day weeks, 10 months in a year, etc.)
I suppose in-grained traditions that are so hard to change (birthdays, memorials, etc.) make this nigh impossible.
It's more that there are 365¼ days per solar year. and seasons happen at ¼ year intervals.
Any calendar will need need to ensure that those relationships can be represented with only minor but consistent variations, e.g. leap years). Weeks largly stem from there being roughly 28 days in a lunar month.
If we're freeing ourselves from any relation to Earth's physical progression through space, e.g. 24 hr day, ~28 day solar month, or 365¼ day year, there would need to be a compelling reason, e.g. being a largely and widespread spacefaring civilization.
I believe that the closest thing that existed was French Republican calendar [1], accompanied by decimal time [2]. The Swatch Internet Time [3] which uses decimal minute at its base is also worth mentioning - it's almost forgotten nowadays.
The ancient Egyptian calendar had 10 day weeks. And the French revolutionary calendar had something similar. But there's nothing particularly superior about a decimalised calendar.
I suppose in-grained traditions that are so hard to change (birthdays, memorials, etc.) make this nigh impossible.