HYSPLIT Forum: hysplitbbs.arl.noaa.gov

Hi, I haven't used this HYSPLIT website for a long time, the analysis page has changed, When I select GFS (0.25 degree...),I could only see 1st May or 2nd May for the starting date. I have to ask that how can we select a random (the date that we wanted) starting date for backward trajectory analysis...