departure
ご出発は何時ですか？
What time will you be leaving?
ご出発の時刻をお知らせ下さい。
Please let us know your departure time.
明日のご出発は何時ですか？
What time will you be leaving tomorrow?
ご出発を前もってお知らせください。
Please let us know in advance when you will be leaving.