Take Out the Papers and the Trash
Berel and Shmerel are sitting on a bench in the middle of Chelm, chatting. Berel asks Shmerel, "Has your son Chaim Yankel decided what he wants to be when he grows up?"
"Yes, he wants to be a garbage collector," replied Shmerel.
Berel thought for a moment and responded, "That's a rather strange ambition to have for a career."
"Not really," said Shmerel, "It should be an easy job.”
“How so?” asked Berel.
“Because garbage collection is only done on Tuesdays."