The official rules are that choice of rafsi should not affect the meaning of
a lujvo, so at least in principle {pavdei}, {pavdje} and {pavdjedi} should
all have the same meaning.
The same problem of months applies in the case of days, the most
direct interpretation of {zeldei}, based on place structure, is "week".
There are no common words in English for "two-day period",
"three-day period" and so on, but that's what place structure
suggests.
Another issue with them might be the confusion that such names
could cause to people such as Portuguese speakers whose native
language calls "Monday" the second day, and so on. I don't know
how bad that problem would be for them.
There is an international standard, ISO 8601, which states that Monday is numbered 1 and Sunday 7. It might be wise to align the Lojbanic numerical system with this. Some people will always opt for a numerical system, so we ought to pick one & stick with it. Jbovlaste currently aligns with ISO 8601.
I actually like the Japanese and Korean system:
soldei Sun's day
lurdei Moon's day
fagdei day of the planet of fire (Mars)
jaurdei day of the planet of water (Mercury)
mudydei day of the planet of wood (Jupiter)
jimdei day of the planet of metal (Venus)
derdei day of the planet of earth (Saturn)
Planet-based names are in use in much of Europe and India as well. I guess I'd like to see {-pliny-} in the last five, but then they'd be too long.
mu'o mi'e komfo,amonan