Inspired by We had a unit test once which only failed on Sundays, write a program or function that does nothing but throw an error when it is Sunday, and exit gracefully on any other day.

###Rules:

• No using input or showing output through the usual IO methods, except to print to STDERR or your language's equivalent. You are allowed to print to STDOUT if it's a by-product of your error.
• A function may return a value on non-Sundays as long as it doesn't print anything
• Your program may use a Sunday from any timezone, or the local timezone, as long as it is consistent.
• This is code-golf, so the shortest bytecount in each language wins!

I'll have to wait til Sunday to check the answers ;)