How do defining the first and last day of the month

I have a question for you. Is there a chance to create a macro something similar to this, but in prco sql in quera where it always selects the first day and the last of the month.

%let thismonth=%sysfunc(putn(%sysfunc(today()),yymmn6.));

    where t1.DATE = &thismonth
        and _dly.  between t2.data_from and t2.data_to 
        and &gv_date_dly.  between t3.data_from and t3.data_to 
        and t3.obj_code not in ('G07','N06','N07') 

where we have date from to be recalled from the 1st day of the month and date_to to the last day of the month when the function & thismonth was called