It depends on a number of variables. Of primary importance is your career goal. Do you want to be a major airline pilot? A regional airline pilot? A corporate pilot? A flight instructor?

The short answer is, I'm an airline pilot and this is a second career for me. Additionally, I fly with many Captains that have had other non-flying careers and are doing very well with flying.

The long answer is, you should expect at least 4 years from the time you start flying full-time before you can be employed at a regional airline and at least 6-10 years before you can be employed at a major carrier. These numbers could be an underestimate and are based on ideal conditions...