Your last chance to fly with Virgin America is April 24, 2018.
Now, an internal Alaska Airlines memo obtained by FlightGlobal and later confirmed by the carrier reveals that "guests who try to book a . . . flight scheduled for after April 24 through Virgin America's website or app will be redirected to AlaskaAir.com."
As of April 25, those flights "will be Alaska flights and will only be available through Alaska channels," according to the memo. Even now, some flights that, when booked, may appear to be operated by Virgin America may in fact be operated by Alaska.
In any case, by late April the company will no longer maintain separate Virgin and Alaska websites, mobile apps, and ticket kiosks.
You have six months to say your goodbyes.