break of day

:  to separate into parts with suddenness or violence

:  fracture

: to fracture a bone of (a bodily part)

:  an act or action of breaking

:  the opening shot in a game of pool or billiards

:  a gap or opening caused or appearing as if caused by damage :  a condition produced by or as if by breaking :  gap

:  the time of light between one night and the next

:  daylight

:  daytime