Final answer:
In Shakespeare's play, Brutus instructs Lucius to check the calendar to learn that it is the Ides of March, the forewarned date of Caesar's death, which marks the significant event of Caesar's assassination on March 15th, 44 BCE.
Step-by-step explanation:
Brutus wants Lucius to look at the calendar to find out the current date. This occurs in William Shakespeare's play Julius Caesar, where Brutus is involved in the conspiracy to assassinate Caesar.
The significance of what Lucius finds is that it is the Ides of March, March 15th, which is the day that Caesar is forewarned to beware, suggesting his impending doom.
In the context of Rome's history, the Julian calendar introduced by Julius Caesar, which included the concept of leap years, would have been the calendar used during this time.
The play reflects historical tensions and conspiracies that surrounded the end of the Republic and the rise of the Empire, with the Ides of March being a pivotal moment in Roman history when Julius Caesar was assassinated in 44 BCE.