"Will you eat lunch with us today?"
Translation:Wirst du heute mit uns zu Mittag essen?
For simple sentences, adverbs in German are usually placed in the first or third position (i.e. right before or right after the verb) depending on emphasis. This is especially true with time based ones (morgen, gestern, heute, etc.).
Since "heute" is an adverb it would be placed right before after "wollen" in this sentence if it was declaritive. But since this is a question, the verb has to go first, followed by the subject, then the adverb, then the rest of the sentence.
Hope this helps!
Although other orders are possible, I think that the TMP rule for the "standard" placement order of adverbs might still be useful here. Under this rule the Time-based adverb (heute) is normally placed before the adverb indicating the Manner (mit uns). Here is a link on word order that I found interesting (refer to IV. The Mid-field for positioning of adverbs) http://www.dartmouth.edu/~deutsch/Grammatik/WordOrder/WordOrder.html
Much confusion here. Apparently, there is a noun, Mittagessen, which I thought this was. (Not just Austria, as commented below). But if "zu Mittag" is to be separated from "essen," doesn't it become "time" and have immediately follow the verb? Same with "heute," also an indicator of time.