P3460 Date Patterns

In the Forecast program P3460, Forecast dates are Ok through 1/31/2015. It then jumps to 3/1/2015 and uses the first of the month through November. December has 2 dates, 12/1/2015 and 12/31/2015. January 2016 is correct then the rest of the months use the next to last day of the month. I verified the Date Patterns in the f0008 file and they are all correct. Where do I find where the forecast program is getting these dates and how do I correct them? Thanks!