Oh yes! DS went through a serious clock phase around 21 months. Every time he saw a digital clock he'd ask what time it was. Within a week or two he could name every number up to 100. This obsession also included timers. He'd set them on the oven and microwave and watch them count down.
At 4 he's still pretty interested in time, but I wouldn't call it an obsession anymore. Timers often go off in our house that I never knew were set. The oven timer goes up to 23 hours and 59 minutes, so sometimes it goes off in the middle of the night or when we're away from the house. He never really went through the same thing with analog clocks, but at some point during his three year old year he learned how to read them. And he's also fairly good with elapsed time. The other day DH ordered a pizza & announced that it would be ready in 30 minutes. DS looked at the clock (4:46), thought for a moment, and said it would be ready at 5:16.
That's all "normal", right?
ETA: Ok, now I'm remembering a short analog clock interest before the digital clock obsession. It think it was mostly about the numbers though. I remember him telling me that "X is 10" at my MIL's house. Finally I realized that her analog clock was in Roman numerals.
