'Nights' in the Bible

After He had gone without food for forty days and forty nights, He became hungry.

for just as Jonah was three days and three nights in the belly of the sea monster, so will the Son of Man be three days and three nights in the heart of the earth.

in labor and hardship, often unable to sleep, in hunger and thirst, often [driven to] fasting [for lack of food], in cold and exposure [without adequate clothing].