I was thinking about this phenomenon today. Digital clocks are so common now that I don't often need to read an analog one, much less in a hurry. I worry that I'm losing the ability to do so. (The worry is a little bit because I might still need it at some point, and much more because being able to quickly read analog clocks makes me feel like a grown-up.) In particular, when I am called upon to read one, I'm embarrassed by how long it takes me to do so. It's only several seconds, but that's enough to make it clear to anyone watching that I had to stop and think about it.
But then I caught myself, and thought, wait a moment. Am I actually much slower at this than I used to be? Or is reading an analog clock really just a noticeably slower action than reading a digital one? This is intuitively plausible; it has more mental steps. Rather than comparing my current analog-clock-reading speed with a previous one (which I don't really remember), I'm comparing it to my digital-clock-reading speed, which doesn't make sense. I was going to ask how you'd design an experiment to test this. Then I remembered that not everyone is young enough to have to speculate about what it's like not having mostly digital clocks around. :P So if you're old enough to have significantly more practice reading analog clocks than digital, how long does it take you to read one? Is it noticeably longer than reading a digital clock? If you aren't, and have a significantly different experience from mine, I'm interested in that too.
I find that I may spend more time parsing the result from an analog clock when someone asks me to say what time it is (generally the problem is when I perceive the minute hand to be halfway between two of the markings). HOWEVER, an analog clock has a key advantage for me over a digital one -- 7:34 when I have to leave at 7:35 does not make me nearly as desperate to go as when my watch gives the same reading. I think it's because digital clocks make me see the glass as half-full (since I always know exactly how much time there is left) while analog clocks make me see the glass as half-empty (since my watch is almost always at least two minutes off in some direction no matter what I do).