Can you meditate too much as part of a daily routine?

Just to follow up from this question - is it possible for an individual to meditate too much? Is there a point when it becomes counterproductive and if so what would the signs be that someone should slacken off their meditation routine? Just to be clear - I am talking about a meditation routine outside of a retreat setting. The question is about someone's daily meditation routine rather than during a retreat when the conditions and level of support one would receive would be very different.