DateTime Compare Function

hi,
I have the following function that returns always 1 no matter what:
for (i = 0; i <= Count - 2; i++) {
            for (j = 0; j <= 6; j++) {                
                 strWeekDay = DateTime.Today.AddDays(DateTime.Compare(DateTime.Today.AddDays(j), StartTime)).ToString("dddd");
...etc
  }
}
When I run it (Today) it always return Saturday!. I tried the compare function on its own and namtter what I enter for the StartTime (DateTime Variable) it always returns 1

I am trying to get the difference between the two sates in Days of the Week (Sunday, Monday...)

any idea how to fix it?
I am using ASP.NET - C#