Although it's no longer 2012, apparently people are still watching the YouTube video for Korean pop star Psy's smash hit song Gangnam Style.
The irritatingly catchy tune has racked up so many views that Google has been forced to upgrade YouTube's infrastructure to cope. When YouTube was first developed, nobody ever imagined that a video would be watched more than 2 billion times, so the view count was stored using a signed 32-bit integer.
The maximum value of this number type, 2,147,483,647, is well known to C programmers as INT_MAX. Once INT_MAX is reached, attempting to record another view will normally roll over to -2,147,483,648.
YouTube isn't the only software that this number is a problem for. Unix systems record time values as the number of seconds since 00:00:00 UTC on January 1, 1970. 32-bit systems use a signed 32-bit integer for this, so they will wrap around 2,147,483,647 seconds after that date. Two billion seconds is about 68 years; on January 19, 2038, at 03:14:07 in the morning, 32-bit Unix clocks will roll over.
While not a problem for desktops and servers, which have already made the switch to using 64-bit counts for the time, it's possible that embedded systems will continue to be 32-bit even 24 years from now.
As for YouTube, upgrading to a 64-bit signed number means that Gangnam Style is safe until it reaches 9,223,372,036,854,775,807 views. That's not likely to occur for another 4 billion years or so.