Good Riddles

Question: Why was the calendar worried?

Question: What room can you not go into?

Question: There were 2 trains heading the opposite directions on the same track.1 was going North, and one was going south, There was a 100m gap between them, avoiding the collision, 2 men saved the trains from colliding on time, Who were they and how did they save them?

Question: How do you make seven an even number?

Question: I never sleep yet sometimes I weep. I can get angry or just be happy. Wherever you go I will follow. No matter what you do I will be there. I can not die. What am I?