What about this? (just off the top of my head -- not sure if this will work the way you want)

ltNow = DATETIME()
lnYr = YEAR(m.ltNow)
lnMo = MONTH(m.ltNow)
lnDy = DAY(m.ltNow)
lnDiff = 60    && Adjust to whatever you need
SELECT att_pk;
	FROM AutoTask;
	WHERE (m.ltNow-DATETIME(m.lnYr,m.lnMo,m.lnDy,att_hour,att_min))<=m.lnDiff;
	INTO CURSOR crsrAutoTasks

(the above code will need a few tweaks to work correctly for cases where the hour and date are close to the end of the day)