For those who have worked for other carriers, SW uses reserves completely differently than any other airline. At most airlines reserves are insurance - meant to cover sick calls etc. So you rarely fly, rarely break guarantee, and, if you live in base, can be a great deal to spend time at home. SW uses reserves to cover open time they dont want to pay premium for. So you almost always fly, consistently break guarantee, and lack many of the contractual pay protections provided to lineholders. Also, SW is big about saying "our reserves get more days off than anyone elses" -- which is true IF you live in domicile. Remember that there are only a handful of commutable pairings at SW (reserve or otherwise) so you will typically commute in the night before an AM pairing, or commute home the morning after a PM pairing. So even though you have 15 days off, you'll spend part of 4-5 of those commuting into your domicile. (whether you are on reserve or not)