"In my current position, I collaborate with our offices in the U.S., Canada, Scotland, and Finland. It was a struggle at first to remember what day and time others were working in; however, I now have a great desktop application that tracks this for me."

"I don't have exposure to working around multiple time zones. I imagine the time of day is important to consider when dealing with customers on a global scale. I am not opposed to working outside of business hours if I need to communicate with a client across the globe. Other than cultural differences and how the time of day affects their psychology, what other elements come into consideration when dealing with customers on this scale?"

If you have experience with this, describe it in your answer. If you don't, explain your understanding of the importance of this question.

If you're not sure how to navigate this question beyond the above advice, ask clarifying questions. This will show your eagerness to learn and pick things up fast.