Pruning Portuguese Laurel end of April?

Hi, I have a couple of Portuguese Laurels that have grown rather tall and unsightly about 6 ft high,  online resources suggest that best times for pruning are February, July & September. I did give a couple of others (5ft) a trim last month (I have 4 as large topiary cones) and they seem ok but held back on these two as they needed to be topped by a foot or so however its bugging me no end and tempted to get the hedge trimmer out and just hope for the best, what'sthe worst that can happen?