Yes, you can. Find the place you want to go, then tap the directions icon (the two arrows) and select the public transport result (the train) and then select Leave now. There you can select the time you want to Leave or Arrive at the destination.
To change your departure time, select Leave and choose the day and time you want your journey to start.
To change your arrival time, select Arrive and choose the day and time you want your journey to end.