Making his bad mood worse: another sign created by professionals who don't know the difference between every day and everyday.
For the zillionth time: Every day is an adverb (e.g. I see this inexcusable mistake every day.). Everyday is an adjective (e.g. Mr. Rewrite loves everyday people. Not really.).
Here's one of a thousand online explanations to back up Mr. Rewrite's harangue.
What are these people drinking?!?!?!?