Just to add on to what others have posted... You'll really need to be a line holder to have a good chance to pull this off. DTW on the CRJ is about the only place that might happen at this point. I seriously doubt anyone hired into the 175 in the next few months will be off reserve at that point. Take the CRJ and transfer to your domicile of choice after March.

You'll get what we call Gold Days which are guaranteed days off with no credit associated with them. I believe if you are hired this fall you'll receive five of them for the next year (we get five every calendar year). Come January 1st use those five days spread out over 8 days or so for the time you want off. Bid the days off around them in your PBS bid. Also be willing to let PBS give you anything during the other times of the month. You'll also want to waive minimum credit and bid down to minimum hours. With your seniority it more than likely will not honor that request but give it a try. PBS is still probably going to load up your schedule with 85+ hours. If it gives you locals in between your gold days post them on the swap board. Split Duties are easy to give away in my domicile. I don't know how it is in DTW. You might want to bid those in higher layers. Also bid one day off between work blocks and the property (which I cant remember what it's called) that allows a higher amount of block in 7 days.

Your best bet is to celebrate your birthday at the end of the month and try to get the end of March and beginning of April off. Stuffing that 85+ hours of credit into a month where you are taking nearly two weeks of is almost impossible.

You'll find that a lot of crew members celebrate holidays, etc.. on the days that they don't fall on. Until you get some seniority in your seat you might want to plan on it.