i've never understood what it means. i once asked my sister to explain and she was like "well it means that it's the uh... days of.." to which i interrupted with "their lives?" and she said "yes."
You're kidding right? How the fuck can you not understand that? You don't deserve an answer. You must suffer for your ignorance. On second thought, it is mean not to tell you..... that sucks for you.