Can you meditate too much as part of a daily routine?
I'm sure you've heard the phrase "Practice like your hair is one fire"

However, one researcher was looking for people who had so-called "Dark Nights of the soul" experience, i.e. unpleasant experience with meditation. She found that


  "She identified two susceptible demographics: a) men, 18 to 30 years
  old, who go to Asia and do 10 to 20 hrs of meditation/day, and b)
  middle-aged women w/an hr/day practice who go to “say, Spirit Rock
  Meditation Center ... for the last 10 to 20 years”.


ref: http://beyondmeds.com/2014/02/16/dark-night-of-the-soul/

In the case of a lay follower, I don't think we need to go outside of Buddhism to answer the question-- your job will determine the upper bound to how much you can meditate, which I suppose is the whole motivation behind renunciation, to allow more time to meditate. For a lay follower with a day job, fitting in 3 hours a day and maybe more on a weekend (16 maybe?) seems to be the most you can get away with without re-arranging your lifestyle and job to crank up the number of hours.

Anyhow, in my opinion quality trumps quantity, I wish I had a good objective metric for monitoring quality.

Also, in my own practice I've been working on doing more different sorts of meditation, since I already sit on my butt at the office all day staring at a screen (sometimes with concentration, sometimes scatter brained). So I've been trying to mix in prostrations, chants, walking meditation, etc.