You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: I am Cynthia Taylor. Can you please assist me for booking from SFO to DCA?

ASSISTANT: Sure, I am here to help you in booking. Can you please share your travel dates?

USER: My planned dates are on 28 and 30 on the month of April.

ASSISTANT: Please share me your departure time and return time.

USER: My depart time is afternoon and return time is evening.

ASSISTANT: Do you have any specification?

USER: I need single connection.

ASSISTANT: Sorry, no flights are available on your preferable travel dates.

USER: Ok, no issues. Thank you.