Source: Elines
Once Seniority Trades with Open Time have been awarded, Flight Attendants will have the ability to indicate their preference to fly through their January 2018 vacation. This opportunity will likely become available on or around November 30th. Flight Attendants intending to fly through their vacation in January 2018 must notify the company no later than December 5th at 10:00AM Home Domicile time.
Additional details on the Vacation Fly Through Option are available in the 2018 Vacation Modification Guide (page 22).