i need a train out of cambridge
user
okay ! where would you like to go ?
assistant
i want to go to stevenage .
user
these trains run every 2 hour -s , starting at 05:21 . what time would you like to depart ?
assistant
i want to arrive at stevenage by 20:45 .
user
the tr2515 meets your criteria . would you like to book some tickets ?
assistant
does that train travel on friday ? and can i get the total travel time ?