Events recurring every "Weekday" are appearing on Saturday!

I have several conference calls I attend throughout the week and found myself late to several because I'd be listening to something on my iPhone using my Bluetooth headphones and miss the subtle popups from Windows 7 on my work PC. So I started adding them to my iPhone's calendar with reminders to pop up when the calls were to start. The thing is, they made it really hard to schedule a meeting that occurs every work day (Mon-Fri). You have to use the Custom option then choose "weekly" and select the days individually. Well, I've done that. It's to repeat every week on Monday, Tuesday, Wednesday, Thursday and Friday.. The thing is.. When I save the event and go look in my calendar.. it's appearing on Saturday as well! It's not like it's something that flows from one day to the next, it's a 30 minute event. How do I stop it from appearing on Saturday? Why can't we have a simple "Weekday" repeat option??