Dr. Kate Forster (Sandra Bullock) lives in 2006, Alex Wyler (Keanu Reeves) in 2004. The lovers connect after a letter Forster intends for the next lake-house tenant time-travels backward to Wyler, who also lives in the house but in 2004. Despite the year confusion, it's nice that (spoiler alert!) they end up, albeit inexplicably, together.
EXTRAS Five nonsensical, thankfully deleted scenes, and a trailer (that's a special feature?). I kept hoping for a making-of brimming with explanations. That would have been even more laughable than the plot.