From the room of the Last Supper to Gethsemane, Christ continued with the Farewell Sermon and taught the apostles (John 15 and 16 chapters). In order for the lesson to be understood and remembered, he indicated the example of the vine and the vine rod that bears fruit, if it is on the vine, and not when it is cut off from it.
After these words, Christ finished his teaching and began the Prayer in Gethsemane. The sufferings of Good Friday begin in Gethsemane.
Good Friday is the day of Christ’s sufferings. They begin at night, in Gethsemane. That is why we count in Good Friday in the Gethsemane events. They happened late at night – after midnight.