As BobyIsProgress posted, increase the date by 1 and check if the new date is a business day:
DEFINE VARIABLE V_yearenddate AS DATE NO-UNDO.
DEFINE VARIABLE V_businessdays AS INTEGER NO-UNDO.
V_yearenddate = Date(12,31,YEAR(TTbatch.cycledate)).
DO WHILE TRUE:
V_yearenddate = V_yearenddate +...