If you meet the mins and you have a rough idea of when you will be available, apply! I've been told it shows desire but if nothing else it will get you going through all of the admin hoops you'll have to go through. The FCC license can take time and if you don't have a passport, that can take time as well as the ATP etc.

I have friends here that have been hired a year or so out, but that was with SWA. My sponsors at the other majors have said what the other folks here have said; and that is don't expect them to call you more than 4 months from your avail date.