SAS macro with conditional loops (%if %then %else %do %end) - if-statement

Question

I'm a beginner in SAS and I am trying to use a macro to import excel files using a conditional loop.
The importing process is based on initial_year ; final_year; initial_month and final_month values.
But it seems the If condition is not working. Can you help please. Thank you.
This is my sas program:
%let path=\\xxxx.yy.pt\aaa$\INFO\;
%let initial_year=2019; %let initial_month=2;
%let final_year=2021; %let final_month=1;
%Macro import_loop;
%if &final_month >= &initial_month %then %do;
%DO x = &initial_year %TO &final_year;
%DO i = &initial_month %TO &final_month;
%if &i <=9 %then %let anomes=&x.0&i;
%else %let anomes=&x&i ;
proc import datafile="&path&x\Farmacias_EA_&anomes..xlsx"
out=Farmacias_EA_&anomes REPLACE dbms=xlsx;
run;
data Farmacias_EA_&anomes;
set Farmacias_EA_&anomes;
Data_anomes=&anomes;
run;
%end;
%end;
%else %do
%DO x = &initial_year %TO &final_year-1;
%DO i = &initial_month %TO 12;
%if &i <=9 %then %let anomes=&x.0&i;
%else %let anomes=&x&i ;
proc import datafile="&path&x\Farmacias_EA_&anomes..xlsx"
out=Farmacias_EA_&anomes REPLACE dbms=xlsx;
run;
data Farmacias_EA_&anomes;
set Farmacias_EA_&anomes;
Data_anomes=&anomes;
run;
%end;
%end;
%DO x = &final_year %TO &final_year;
%DO i = 1 %TO &final_month;
%if &i <=9 %then %let anomes=&x.0&i;
%else %let anomes=&x&i ;
proc import datafile="&path&x\Farmacias_EA_&anomes..xlsx"
out=Farmacias_EA_&anomes REPLACE dbms=xlsx;
run;
data Farmacias_EA_&anomes;
set Farmacias_EA_&anomes;
Data_anomes=&anomes;
run;
%end;
%end;
%end;
%mend import_loop;
%import_loop

Answer 1

Just treat your dates like dates and the looping will be much easier.
%macro import(from,to);
%local start end offset yymm year ;
%let start=%sysfunc(inputn(&from.01,yymmdd8.));
%let end=%sysfunc(inputn(&to.01,yymmdd8.));
%do offset=0 %to %sysfunc(intck(month,&start,&end));
%let yymm=%sysfunc(intnx(month,&start,&offset),yymmn6.);
%let year=%substr(&yymm,1,4);
proc import datafile="&path.&year.\Farmacias_EA_&yymm..xlsx"
out=Farmacias_EA_&yymm. REPLACE dbms=xlsx
;
run;
data Farmacias_EA_&yymm.;
set Farmacias_EA_&yymm.;
Data_anomes=&yymm.;
run;
%end;
%mend import ;
%let path=\\xxxx.yy.pt\aaa$\INFO\;
%import(201902,201201);
Do you really want the variable DATA_ANOMES to have numbers like 201,902 ? Why not either store it as a string like "201902" or an actual date value like "01FEB2019"d ?