Yes, it would mean the same thing. Also, in your sentence, you should write "every day" as two words. "Every day" is an adverbial phrase, and means "on all days, without exception." "Everyday" (one word) is an adjective which means "used or encountered routinely". Example: "My everyday shoes are very comfortable". Here's both "every day" and "everyday" in one sentence: "I wear my everyday shoes every day."

If you change the word "except" to the word "but", people can still understand what you mean. But it would be a lot better if you wrote it this way: "I go to work everyday except during Sundays"

You may as well use "other than" to substitute "except".