The United States is spread across six time zones. From west to east, they are Hawaii, Alaska, Pacific, Mountain, Central, and Eastern.
Imagine that you live in Philadelphia, Pennsylvania at 75 degrees west longitude. It is three in the afternoon, Eastern Standard Time, and you call your grandparents in Reno, Nevada at 120 degrees west longitude.
13. What time is it in Reno (Pacific Standard Time) when you call?
Consider other cross country calls you could make. Are there certain times you shouldn't call from one zone to another if you don't want to disturb people at night?