Disturbed by Caesar's unbridled power and by the convincing arguments of Cassius and Casca about the danger to the republic is Caesar is allowed to continue his willful use of power, Brutus awakens in the night and goes to his orchard outside his chamber. As he enters, he calls for his servant Lucius. As he does so, Brutus looks up to the heavens and says to himself that he cannot "Give guess how near to day" it is. Lucius is sound asleep and does not awaken easily, so, perhaps, Brutus thinks it is still late.
In ancient times, the hour of the day could be told by sundials. However, once night had fallen, telling time was truly difficult. The best that people could do was what the sailors of old did: They looked to the North Star and the Big Dipper. Since the earth rotates, the North Star, which many a clipper ship of old depended upon, moves around to different constellations. So, if a person knows astronomy, he/she can tell time on a clear, bright night. When, for instance, the "pointer" stars of the Big Dipper are directly above the North Star, it is 11:oo siderial time (time told by the stars). When the pointers are beneath the Big Dipper, it is 23:00 siderial time. In order to convert siderial time to solar time, a person must add 4 minutes to sun time for each day after March 21 when the equinox occurs.