IMPORTANT UPDATE: I didn't see Toliet Roll Clock's Flash before I thought of this, I am currently trying to contact him to apologize for seemingly stealing his idea. :( I promise not to make any more until I have spoken with him.
This is totally unrelated to Clock Day, I just used clocks cause they are easy to draw...
To understand this you should have seen the movie: "Clerks" or even better, the short animated series: "Clerks"
Don't forget to try and find the Easter Egg! It's pretty hard!