I know this may sound absurd, but I feel like it's definitely a legitimate question...
To preface - I'm currently looking for full-time employment as a software developer, and I've progressed past the grueling phone/technical interviews with a handful of companies that want me to come in for in-person interviews next week. Most of these companies are laid-back tech firms in the SF Bay Area - not IBM in the 70's - but I still find it's best to come to an interview well-dressed and clean cut (even when some of the employees have nose rings and tattoos). I typically like to grow a beard, and also shave my head (I started losing my hair a couple years ago in college), but neither of these are a recommended look for an in-person interview. So I've been shaving my face and letting my hair grow out. No matter how ridiculous I feel, it's totally worth it for me because these are some of my dream jobs.
My question is essentially this: if I am offered a position with one of these companies, and I accept, how long should I wait after I start to begin growing a beard and shaving my head again? In my experience it's never a good sign when a new employee comes in appearing to be a completely different person on their first day, opposed to who they appeared to be when they were when offered the job. I'm sure most everyone has experienced what I'm talking about to some degree. Someone that seemed like they'd be a great hire, but once they started it was apparent they were only there to collect a paycheck. I just don't want to come across that way - I truly am seeking employment for much deeper reasons than pay...programming is my passion.
I would just like to hear some people's recommendation as to what a professional standard would be for a situation like this. I appreciate any advice!