On my system, the times HCA computes for sunrise and sunset are way off. What could be wrong?
This may be due to one of two problems. The location you selected when you created your home design was incorrect. You can check this by using Home->Properties and the location tab in that dialog. Either enter the latitude and longitude of your home or chose a nearby city. The other problem may be the time zone is not correct for your location. This can be checked from the Windows Control Panel Date/Time applet. The time zone you select must be compatible with the location selected for your home design.