I had a friend who was looking for Administrative Assistant roles with a 2 year gap on her resume and it was a problem. The companies could always find a younger person to sit in the chair and do the menial tasks, and somebody with no gaps is more likely to stay put. They also marked her down in interviews for not knowing the latest Excel version (even though she knew Excel and had been using it for years, like anything significant had changed in a year). So jobs like that are kind of shitty to applicants.

But you as a programmer? I cannot imagine it being a problem. You are a high-skill worker who earns enough that you can easily afford to take the time off. Just say you were exploring personal projects in your spare time. That sounds awesome.