You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Joshua Evans here. I want to take my children to Oakland Zoo in OAK, can you please help me to book a flight ticket from DCA?

ASSISTANT: Sure, please share your planned trip dates?

USER: I will depart on Sept 22nd and will return back on Sept 24th.

ASSISTANT: Let me know your connection limit?

USER: I don't have any connection limit.

ASSISTANT: Please share if you want to travel in any specific time?

USER: Yes, I want to depart in the evening and return in the afternoon time.

ASSISTANT: Sorry to say you that, currently no flights are running on this route.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.