A.T. Robertson Commentary John 6:16

"And when evening came, his disciples went down unto the sea;" — John 6:16 (ASV)

When evening came (ως οψια εγενετο). "The late hour" (ωρα understood), and so in late Greek the adjective is used as a substantive. It is late evening (real evening), not the early evening in mid-afternoon (Matthew 14:15). The disciples were in no hurry to start back to Bethsaida in Galilee , Capernaum in John (John 6:17).