In our Lord's time the Jews had adopted the Greek and Roman division of the night into four watches, each consisting of three hours, the first beginning at six o'clock in the evening ( Luke 12:38 ; Matthew 14:25 ; Mark 6:48 ). But the ancient division, known as the first and second cock-crowing, was still retained. The cock usually crows several times soon after midnight (this is the first crowing), and again at the dawn of day (and this is the second crowing). Mark mentions (14:30) the two cock-crowings. ( Matthew 26:34 ) alludes to that only which was emphatically the cock-crowing, viz, the second.
Source
- part_of
source-manifest/easton— Easton's Bible Dictionary (PD)