You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am Kathleen Johnson. I am planning to attend music concert at DCA, can you please help me with booking a flight ticket from SFO?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: Sure, I would like to take off on Aug 27 and return on Aug 29.

ASSISTANT: Ok, please allow me a moment.

USER: I would like to depart during morning time and return during evening time.

ASSISTANT: Sorry, there is no flight with your requests.

USER: Ok, no issues. Thank you for the information.

ASSISTANT: You are welcome, have a great day.

USER: You are welcome.