CSV files are just text files. So there is no need to "import" them. Just write a data step to READ the file instead. Then you have complete control over how each variable is defined.
data want;
infile cards dsd ;
input dt :anydtdtm. ;
format dt datetime19.;
cards;
2020/09/11 02:14:27
2020/09/11 02:15:37
2020/09/11 02:16:08
;
Obs dt
1 11SEP2020:02:14:27
2 11SEP2020:02:15:37
3 11SEP2020:02:16:08