Can't Change MC Username

Hi! I ain't really 100% sure if this is the place for this bug. I'm new here so if it's not please don't judge -. Anyway, I wanted to change my mc username but it still said I had to wait an extra day. I understand I can only wait every 30 days but I've changed my username on April 9th, 2017. Today is the 30th day. I'm not sure if I have to wait another hour or so but please help. I usually have no issues but this is a first. Thanks =D