Where Clause Date Error

[deleted_user]

How do I correct the error noted below. Thanks

The sale date variable is formated as below:
informat sale mmddyy10.

101 WHERE (ST = 'WY') AND (sale BETWEEN '07/31/08' AND '06/30/09') ;
ERROR: Where clause operator requires compatible variables.
102 run;

[Flip]

WHERE (ST = 'WY') AND (sale BETWEEN '31/JUL/08'D AND '30/JUN/09'D) ;

You need to convert the dates to SAS dates.