"We'll Meet Again", the song that Dr. Neiman leaves for Castle and Beckett, is perhaps most well-known for its use at the end of Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb (1964) when the nuclear bomb detonates.
Buddy, I'm gonna have to ask you to move along.
As Beckett and Castle are visiting the Plastic Surgeon, it is plainly daytime through the office windows. However, Beckett then receives a phone call from Detective Ryan who is starting a raid on a private boat, but his scene is taking place at night. Then it cuts backs to Beckett in conversation still in the daytime.