The Lake House (2006)

A lonely doctor (Sandra Bullock) who once occupied an unusual lakeside home begins exchanging love letters with its newest resident, a frustrated architect (Keanu Reeves). When they discover that they're actually living two years apart, they must try to unravel the mystery behind their extraordinary romance before it's too late. Feeling that it's time for a change in her life, Dr. Kate Forester (SANDRA BULLOCK) leaves her suburban Illinois practice for a job at a busy Chicago hospital. One thing she is reluctant to leave behind, though, is the uniquely beautiful house she has been renting - a spacious and artfully designed refuge with large windows that overlook a placid lake. It's a place in which she felt her true self. It is a winter morning in 2006. On her way to the city, Kate leaves a note in the mailbox for lake house's next tenant, asking him to forward her mail and noting that the inexplicable painted paw prints he might notice by the front door were there when she moved in.
But when the next tenant arrives, he sees a much different picture. Alex Wyler (KEANU REEVES), a talented but frustrated architect working at a nearby construction site, finds the lake house badly neglected: dusty, dirty, overgrown with weeds. And no sign of paw prints anywhere. The house has special meaning for Alex. In a happier time it was built by his estranged father (CHRISTOPHER PLUMMER), a renowned architect who let his professional acclaim grow at the expense of his family life. Alex feels a sense of peace here now and commits to restoring the property to its original beauty. He disregards Kate's note until, days later, while painting the weather-beaten jetty he sees a stray dog run across the fresh paint and then towards the entrance of the house, leaving paw prints exactly where she said they'd be.
Baffled, Alex writes back, saying that the house had no occupant before him and wondering how she could have known about the dog; while Kate, who just left it a week ago imagines he is playing some kind of joke on her and fires back a reply. Just for argument's sake, what day is it there?