The deals, however, come with some fine print, so you probably shouldn't start packing just yet. In particular, you'll have to travel sometime between November 8, 2017 and February 14, 2018, although there are a bunch of blackout dates around the holidays. As usual, the sale only applies to JetBlue's "Blue" fares, which means you'll have to cough up another $25 to check a bag, and $35 for a second bag.
All said, this could be your chance to use those extra PTO days that won't rollover into the next year before they're gone. Don't mess this up.