Definition of "tonight"

Besides, I met Lord Bigot and Lord Salisbury,With eyes as red as new-enkindled fire,And others more, going to seek the graveOf Arthur, whom they say is killed to-nightOn your suggestion.

1596, William Shakespeare, The Life and Death of King John, act 4, scene 2, page 165

I dreamt tonight that I did feast with Caesar,And things unluckily charge my fantasy;

1599 (first performance), William Shakespeare, “The Tragedie of Iulius Cæsar”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene iii]