It looks like DATEAMPMw.d variables are being incorrectly auto mapped to being date instead of datetime via haven::read_sas().
At least from the docs:
DATEAMPMw.d - Writes datetime values in the form ddmmmyy:hh:mm:ss.ss with AM or PM.
link
Repex:
sas
libname here "./";
data here.dat;
format us_dt_ampm_short DATEAMPM19.5 ;
input reference :datetime20. ;
us_dt_ampm_short = reference;
datalines;
01JAN2024:12:34:56.8765
30JUL1756:00:45:00.1234
03MAR2092:01:55:10.0987
25DEC2024:23:05:20.6789
;
run;
R
x <- haven::read_sas("dat.sas7bdat")
class(x$us_dt_ampm_short) # "Date"
attributes(x$us_dt_ampm_short)$format.sas # "DATEAMPM19.5"