Now you're just being pedantic - displaying the number of days since a picture was taken is not worse than not being able to differentiate past 12 moths.
No, he isn't being pedantic. It's a real, valid usability issue.
"783 days and 4 hours ago" really is worse. If I am browsing a photo and look at that, my first reaction is "That photo was taken a long time ago". If my buddy asks when that happened, I'll have to start doing some simple math in my head. "Uhh, around two years ago? So what, that's 2010?"
Simply putting the date would have been a much friendly solution. You know immediately that it was "a long time ago" because everyone knows what the current year is. And you know what year immediately.
Conversely, on short scales it's opposite. I don't really care if a post was on Monday or Tuesday (usually). I care that it was recent. Providing the exact timestamp doesn't help.
Think about the task of correlating online events with events from your memory.
Suppose you see a quote from you, saying something rude that seems out of character. Knowing that it was however many hundreds of days ago is useless; see that it was July 27, 2011, at 4am, and you'll say "oh, yeah, somewhere in late July we had X and Y over drinking into the wee hours... those #%#$%s must have been futzing with my computer after I fell asleep, and somehow I never noticed".
Most importantly -- you have to predict the reasons people will be looking at dates, and this varies. Gmail shows both because they can't guess; email can carry so much different stuff.
HN post/comment timestamps beyond a few days ago can be notated in number of days as far as I'm concerned; I don't need to know what year, even -- just "this is old".
The timestamp on a blood sugar reading should include time of day (and possibly day of week even) -- a full timestamp, minimum -- to be useful.
What is that, like two years ago, oh maybe just over 2 years, oh shit no just under...
We have a standardized date system. It's been in use around the globe for years. It works. Please use it.