WordNet sense 1 (the time for one complete rotation of the earth relative to a particular star, about 4 minutes shorter than a mean solar day):

sidereal day

WordNet sense 2 (the time after sunrise and before sunset while it is light outside):

daylight, daytime

WordNet sense 3 (time for Earth to make a complete rotation on its axis):

mean solar day, solar day, twenty-four hour period, twenty-four hours

WordNet sense 4 (United States writer best known for his autobiographical works (1874-1935)):

Clarence Day, Clarence Shepard Day Jr.