Singer Willie Nelson has canceled all of his February tour dates, including his upcoming Panama City show, because of illness. The 84-year-old Nelson was scheduled to play at the Marina Civic Center on Saturday. The concert was sold-out and organizers are hoping to reschedule, but a makeup date has not yet been announced. Jennifer Jones, executive director of the Bay Arts Alliance, said tickets purchased for Saturday’s cancelled show presumably will be honored at a future date. Nelson’s spokespeople said he is recovering from the flu, but his voice needs more time to recuperate.