I agree that getting into trading without good programming skills SEVERELY limits your options and income potential.
As far as how much you need, it depends. Some trading positions require only light programming, VBA for simple analysis on data in Excel/SQL. You could achieve this level of proficiency with a few months of hard self-study.
(I got lucky, and I happened to get a good job without much in the way of programming skills. I recently started a professional Master's program in computer science, though, to remedy the situation. So far, it has been an intense introduction, and I expect to have a fairly useful programming skillset within a year. I highly recommend such a program to aspiring traders.)