Twenty minutes past four
They are like the fire-flies in Cuba , which the Cubans are said to put into a glass box and get light enough from to read by . Here they would need only one , if it could be induced to give its light continuously . '' Having found an open space on high ground , they sat down , and Bearwarden struck his repeater , which , for convenience , had been arranged for Jupiter time , dividing the day into ten hours , beginning at noon , midnight being therefore five o'clock . `` Twenty minutes past four , '' said he , `` which would correspond to about a quarter to eleven on earth . As the sun rises at half-past seven , it will be dark about three hours , for the time between dawn and daylight will , of course , be as short as that we have just experienced between sunset and night . '' `` If we stay here long , '' said the doctor , `` I suppose we shall become accustomed , like sailors , to taking our four , or in this case five , hours on duty , and five hours off . '' `` Or , '' added Ayrault , `` we can sleep ten consecutive hours and take the next ten for exploring and hunting , having the sun for one half the time and the moons for the other . ''