Jesus" "we" probably refers to Himself alone, though He could have meant Himself and the disciples. Jesus later spoke of His disciples continuing His work ( John 14:12; cf. John 20:21). The day in view is probably a reference to the daylight made such by the Light of the World"s presence on the earth. Darkness would descend when He departed the earth and returned to heaven (cf. John 12:35). The nighttime when no man can work may refer to the spiritual darkness that will yet engulf the world. I doubt that this is a reference to the Tribulation. [source][source][source]