What can I say? It's a geeky pun.

Cron vs. Tron - an easy mistake to make.

Panel 1: Two Spacedudes are standing in front of a bank of computers. Showing on a giant view-screen is what looks like a computer game.

Red-suited Spacedude (pointing at the screen):

I said we'll need to make nightly database backups with a cron job!!!