I've heard rummors that requesting days off too often can get you into trouble. If this is true than how come others you work with reguest the same days off every week and get them with no consiqence?
You can select 2 days a week that you are unavailable to work. therefore the people who keep getting the same days off probably have put in on their availability schedule that they can't work those days. fill one out and you can get the same benefits. you can request as many days as you want off, you'll just end up pissing off whoever rights your schedule.