That is something you need to make sure and tell your doctor about. It is really important and can be a sign of some dangerous and not so dangerous things. The reason it is happening or with your feet in the afternoon and evenings is because you have been on your feet or had your feet hanging down for several hours. I have this issue on and off for a couple of years and one of the best things to do is to make sure you put your feet up when you are sitting down. (I used to use my trashcan under my desk when I worked). Give it a shot and see if that helps. Let us know how it goes!