It really depends on how senior you are. Also if you encounter reserve initially there won't be a whole lot of flexibility and you'll have minimum days off. If the airline you choose tends to have higher credit trips you'll most likely see half the month off or more once you hold a line. The more senior you become, the more you can cherry pick your schedule. There are a lot of X factors with your question, but generally you can accomplish what you asked in your original question with a little bit of seniority. I bid about 20% in base and just got off a three week vacation which all I had to do was request a week of vacation, bid around it, and drop a two day trip. So it's all relative.