Expositor's Bible Commentary Commentary John 6:17

"and they entered into a boat, and were going over the sea unto Capernaum. And it was now dark, and Jesus had not yet come to them." — John 6:17 (ASV)

“Evening” could be any time in the afternoon shortly before sunset. The disciples probably hoped to cover the short distance between Bethsaida and Capernaum while daylight lasted, but darkness had already fallen before they actually began to cross the lake. The fact that “Jesus had not yet joined them” may imply that they half-expected him to do so and waited until the last minute, hoping that he would come.