public DateTime GetLastSaturday()
{
var lastSaturday = DateTime.MinValue;
if (this.DateTime.DayOfWeek == DayOfWeek.Saturday)
lastSaturday = (this.DateTime.Hour < 12) ? this.DateTime.AddDays(-7) : this.DateTime;
else
lastSaturday = this.DateTime.AddDays(-(int)this.DateTime.DayOfWeek - 1);
lastSaturday = lastSaturday.Date.AddHours(12);
return lastSaturday;
}