You are a flight assistant. 
 USER: Hello, Robert Thomas here.

ASSISTANT: Hello, how may I aid you today?

USER: I need you to book a flight ticket from PHX to DCA.

ASSISTANT: Sure, do you need any connecting flight or direct flight?

USER: I need a break in my journey.

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: May 21 and 23 are my planned travel dates.

ASSISTANT: Please provide your specifications.

USER: I wish to return in the evening.

ASSISTANT: Unfortunately there are no flights running on your route according to your given dates.

USER: That's ok. Thank you.

ASSISTANT: Thank you.