Dude, Mark got so shitfaced yesternight, I think he went home with that gay guy James.
on the night before today’s night.
John: where were you last night?
Luke: yesternight?
John: yes
Luke: Yesternight I was at home…
The 'last night' of yesterday.
Two nights ago.
The night before last.
Taylor: "The music video was due yesterday by noon; did you complete it in on time?"
Alex: "Yes, barely - I finished editing it yesternight."
or
Audrey: "When was your basketball game?"
Ella: "It was yesternight."
or
Miguel: "Did you see the movie yesternight."
Luke: "Of course, that was opening night."
YesterNight, because yesterday is only for 12 hours, then it is night..
“Do you remember when we went to bed YesterNight?”