“One.”/“How many time travelers does it take to ruin a joke?”

A time travel riddle was posted on Reddit—Jokes on March 20, 2015:
   
“One.”
“How many time travelers does it take to ruin a joke?”
   
   
Reddit—Jokes
Posted by u/[deleted] March 20, 2015
One.
How many time travelers does it take to ruin a joke?
COMMENTS
itisike
This was already posted next week.
 
righteousguy11
prepost
     
Twitter
🏴‍☠️ ＢＬＡＣＫＢＥＡＲＤ  🏴‍☠️
@xBlackbeard
One.: How many time travelers does it take to ruin a joke?  submitted by SpiggleWiggle [link] [comment] http://bit.ly/1Gz2etM
11:32 AM - 20 Mar 2015
 
Twitter
Eric Alper 🎧
@ThatEricAlper
One.
How many time travelers does it take to ruin a joke?
6:30 PM - 3 Jun 2019
     
Twitter
Phil Kollin
@DerbyCityPhil
I’m straight up stealing this from @ThatEricAlper because it’s the most clever/hilarious thing I’ve seen on the Twitter in a while:
One.
How many time travelers does it take to ruin a joke?
7:35 PM - 4 Jun 2019
 
Reddit—Cleanjokes
Posted by u/kickypie June 3, 2019
One.
How many time travelers does it take to ruin a joke?