The word in the sentence that is an adverb is "today".
Explanation:
"Today" is the adverb in the sentence. It is an adverb of time. Adverbs of time tell us when an action happened, but also for how long, and how often. When you put an adverb that tells us when an action happened at the end of the sentence, that is neutral position. But adverbs can be placed in different positions for the purposes of emphasis. For instance, in this case, it is in initial position in the sentence. Consequently, this time element is emphasized.
