“Nitrogen” has nothing to do with “night,” but there are jokes. This riddle was posted on tumblr on December 21, 2012:
     
Q: What happens to nitrogen when the sun rises?
A: It becomes daytrogen.
     
“what happens to nitrogen when the sun comes up? it becomes daytrogen” was posted on Twitter by chip later on December 21, 2012.
   
     
Wikipedia: Nitrogen   
Nitrogen is the chemical element with the symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772. Although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first. The name nitrogène was suggested by French chemist Jean-Antoine-Claude Chaptal in 1790 when it was found that nitrogen was present in nitric acid and nitrates.
   
tumblr (December 21, 2012)
rneerkat:
what happens to nitrogen when the sun rises
it becomes daytrogen
snapfox
I’m going to bed.
rneerkat:
good nitrogen
 
Twitter   
alicia
@Vantas_
‘what happens to nitrogen when the sun rises
it becomes daytrogen’
2:39 AM · Dec 21, 2012·Twitter Web Client
   
Twitter
motherofdragons
@MissKylaKy
rneerkat: snapfox: rneerkat: rneerkat: what happens to nitrogen when the sun rises it becomes daytrogen I’m… http://tmblr.co/ZtpzNyZpvZvL
2:41 AM · Dec 21, 2012·Tumblr
   
Twitter
Isabelle
@isabboob
“what happens to nitrogen when the sun rises?” “daytrogen” “i’m going to bed” “good nitrogen”
10:24 AM · Dec 21, 2012·Twitter Web Client
   
Twitter
chip
@chipgotajob
what happens to nitrogen when the sun comes up? it becomes daytrogen. ha hahahaaa ha..
10:25 PM · Dec 21, 2012·Twitter Web Client
   
Twitter
Elsa Ing
@artsy_elsa
#ThingsILikeToDo make science puns: what happens to nitrogen when the sun comes up? It turns into daytrogen.
9:19 AM · Dec 22, 2012·Twitter for Android
 
Reddit—LibraryofBabel
Posted by u/bluefoot55 August 14, 2013
nitrogen during the day
what happens to nitrogen when the sun rises?
it becomes daytrogen
*
*
*
well…i’m leaving now
good nitrogen
sleep tightrogen
don’t let the bed bugs bitrogen
       
Reddit—Dadjokes
Posted by u/OppositeFingat March 17, 2017
What happens to nitrogen when the sun rises?
It becomes daytrogen
 
Reddit—Jokes
Posted byu/Who_cares_about_name July 10, 2017
A list of puns
(...)
What happens to nitrogen when the sun comes up? It becomes daytrogen.
   
Reddit—Teenagers
Posted by u/eyemareetarrd October 19, 2019
When the sun rised, nitrogen becomes daytrogen
 
Reddit—Jokes
Posted by u/Speakeezies December 27, 2019
What happens to Nitrogen when the sun comes up?
It becomes daydrogen.
   
Reddit—Puns
Posted by u/kickypie February 21, 2020
What happens to nitrogen when the sun comes up?
It becomes daytrogen.
 
Reddit—Puns
Posted by u/kickypie August 21, 2020
What happens to nitrogen when the sun comes up? It becomes daytrogen.
 
Twitter
TheSeireitei
@TSeireitei
Ichigo: What happens to nitrogen when the sun rises?
Isshin: It becomes daytrogen!
Karin: I’m going to bed, you’ve both lost it.
Ichigo: Good nitrogen!
Isshin: Sleep tightrogen!
Ichigo: Don’t let the bed bugs bitrogen!
2:12 PM · Mar 4, 2021·Twitter Web App
 
Twitter
Kaleb Wildman
@KalebWildman1
What happens to nitrogen when the sun comes up? It becomes daytrogen.
From the LMAO app: http://itunes.apple.com/app/id892525499?pt=119655832&ct=Share
1:21 PM · Jul 14, 2021·Twitter for iPhone