The character of Po originated in the first episode of Star Trek: Short Treks (2018), Runaway (2018). Clips from that episode are included in the opening "previously" teaser for this one.
Po says the time travel will require a "Planck level" of energy to create the power of a supernova. One Planck energy unit is around 543 kWh, or around the amount of energy used to operate an air conditioner for a month.
The title of the episodes refers to a line uttered by Juliet in Shakespeare's Romeo, and Juliet. "Good night, good night! Parting is such sweet sorrow, That I shall say good night till it be morrow"
The credits list a "Yeoman Colt" who is not named onscreen. This is the same character that was played by Laurel Goodwin in the original series pilot The Cage (1966)
Opening scene of this episode with the sunrise on the beach is in Toronto, Woodbine Beach.