i am looking for a train to london liverpool street .
user
there are many trains that travel from cambridge to london liverpool street . what day and time would you like to travel ?
assistant
i would like to leave friday and arrive by 17:45 .
user
tr5212 departs from cambridge and arrives at london liverpool street . it leaves on friday 17:59 . would you like to book it ?
assistant
no , that 1 will not work . i have to arrive by 17:45 .