Dedicated to the memory of Amy, the woman who was the inspiration for Before Sunrise (1995). Richard Linklater had spent a night walking and talking around Philadelphia with her, but eventually they lost contact. Some time between Before Sunset (2004) and Before Midnight (2013), he finally learned that Amy had died many years before in a traffic accident, so he dedicated the movie to her.
Richard Linklater, Ethan Hawke and Julie Delpy had an idea to just show Jesse and Celine on a typical day: Someone goes and picks up the kids and it's only later at night that they have this together moment which actually was one of the original ideas behind the title.
The house where they are staying is the famous residence of the late British travel writer Sir Patrick Leigh Fermor, in Kalamitsi, near Kardamili, southern Peloponnese. He left it to the Benaki Foundation on his death in 2011, and the Foundation loaned it to the production. The character of "Patrick" is clearly a nod to the great writer and Hellenophile
Richard Linklater, Julie Delpy and Ethan Hawke have all agreed on interviews that the final thing that made them decide to make the movie was the fact that the three of them are parents and could know how to write that into the characters' live.