This is a classic among most of my friends and family.

During my college days my roommate and I were up talking quite late. As we were about to retire to bed I told her I was going for a run next morning. She said “Sounds, good. Wake me up also.” I nodded.
Next morning I went to her room to wake her up.

Me: “I am going for a run.”
She: “What time is it?”
Me: “9:10”
She: “Hey, don’t confuse me in the morning. Is it 9 or is it 10?”