Reserve/Guard duty is pretty painless at most airlines. I'm not at DAL, but this is how PBS generally works with mil leave...
Before you begin your bid for the next month, PBS will have "pre-assigned" events already loaded into your schedule:
- Carry-over trips from last month
- Vacation
- Training
As long as you notified your airline before the cutoff date for pre-assignments, your military leave should also be pre-assigned. PBS works around all pre-assignments to build you a conflict-free schedule.
Hopefully your airline will assign some "virtual credit" to each mil leave day. This is pay credit which you do not actually get paid for, but is counted by PBS towards your monthly total. Lets say 2.5 hours/day is used...if PBS is targeting 80 hour lines for the month and you take 4 mil days, then you will have 10 hours virtual credit for the mil days. This will result in 70 hours of flying outside your mil time. Otherwise PBS would build you a full 80 hour schedule on the remaining days of the month...which would suck.
Also you can probably get the days before and after your actual drill/AT dates assigned as mil leave if you need to commute.
If you have last-minute mil requirements (after PBS has closed) then they will just have to carve it out of your schedule.