May I know why Invalid date? thx a lot!
data FILTER;
set CRSP1;
where DATE between '1926-01-01'd and '1962-12-31'd;
ERROR: Invalid date/time/datetime constant '1926-01-01'd.
ERROR: Invalid date/time/datetime constant '1962-12-31'd.
ERROR: Syntax error while parsing WHERE clause.

DM'LOG; CLEAR; OUT; CLEAR; ODSRESULTS; CLEAR;';
%LET FOLDER=%STR(C:\USERS\SC\DESKTOP\HIGH);
LIBNAME HIGH "&FOLDER";
DATA CRSP;
SET HIGH.CRSP;
RUN;
DATA CRSP1;
SET CRSP;
PRC=ABS(PRC);
IF SHRCD^=10 AND SHRCD^=11 THEN DELETE;
IF EXCHCD^=1 AND EXCHCD^=2 AND EXCHCD^=3 AND EXCHCD^=31 AND EXCHCD^=32 AND EXCHCD^=33 THEN DELETE;
KEEP PERMNO DATE PRC;
RUN;
PROC SORT DATA= CRSP1;
BY PERMNO DATE;
RUN;
data FILTER;
set CRSP1;
where DATE between '1926-01-01'd and '1962-12-31'd;
run;
proc summary data=FILTER noprint;
by PERMNO;
output out=historical_prices(drop=_:)
max(HIGH) = OHH
min(LOW) = OLL;
run;
data final_data;
merge FILTER historical_prices (keep=PERMNO OHH OLL);
by PERMNO;
where DATE = '1962-12-31'd;
run;